Big Redistricting News Out Of PA!

[AustralianSwingVoter]

Pennsylvania Non-Partisan plan.

My non-partisan redistricting plan for Pennsylvania. Currently the 1st district is plurality black while the 2nd District is majority black, under my plan both are (barely) majority black.

District 1 D+36.23 - 86.0 - 13.5 - 50.5 African American
District 2 D+40.09 - 89.4 - 10.2 - 50.1 African American
District 3 R+07.92 - 49.9 - 48.7
District 4 R+15.94 - 41.1 - 57.8
District 5 R+15.67 - 44.6 - 53.9
District 6 R+03.31 - 53.5 - 45.3
District 7 D+02.38 - 54.2 - 44.9
District 8 R+00.68 - 53.9 - 45.0
District 9 R+23.28 - 37.9 - 60.7
District 10 R+18.38 - 41.1 - 57.6
District 11 R+08.43 - 47.0 - 51.8
District 12 R+03.28 - 48.7 - 50.3
District 13 D+11.61 - 62.1 - 37.1
District 14 D+12.51 - 63.0 - 36.0
District 15 R+00.74 - 55.9 - 42.8
District 16 R+08.66 - 46.4 - 52.7
District 17 D+00.28 - 57.6 - 41.4
District 18 R+13.38 - 44.8 - 54.1

My Pennsylvania redistricting plan.

[AustralianSwingVoter]

Holy hell is that a lot of cut counties - I have drawn maps that only cut 6.

No it isn't, only 16 counties were split between two or more congressional districts, and with 3 being larger than a congressional district, that leaves but 13 counties split.
Also, I don't draw my maps with the sole objective of splitting as few counties as possible, I also take into account urban areas, statistical areas, cultural regions, existing districts and many other factors.

[AustralianSwingVoter]

Holy hell is that a lot of cut counties - I have drawn maps that only cut 6.

No it isn't, only 16 counties were split between two or more congressional districts, and with 3 being larger than a congressional district, that leaves but 13 counties split.
Also, I don't draw my maps with the sole objective of splitting as few counties as possible, I also take into account urban areas, statistical areas, cultural regions, existing districts and many other factors.

Counties are very important as political units, and except in New England probably the most important unit in the US. It is one of the most common items to protect for states that have rules against gerrymandering.

Most certainly, I completely agree with you, however, as I said, I don't think the sole metric of a fair redistricting plan is that it splits as few counties as possible, yes that is a key metric, however it shouldn't be the only aim of redistricting.

[AustralianSwingVoter]

Holy hell is that a lot of cut counties - I have drawn maps that only cut 6.

No it isn't, only 16 counties were split between two or more congressional districts, and with 3 being larger than a congressional district, that leaves but 13 counties split.
Also, I don't draw my maps with the sole objective of splitting as few counties as possible, I also take into account urban areas, statistical areas, cultural regions, existing districts and many other factors.

Counties are very important as political units, and except in New England probably the most important unit in the US. It is one of the most common items to protect for states that have rules against gerrymandering.

Most certainly, I completely agree with you, however, as I said, I don't think the sole metric of a fair redistricting plan is that it splits as few counties as possible, yes that is a key metric, however it shouldn't be the only aim of redistricting.

The problem I have observed is that some criteria that sound good actually are quite subjective. These criteria are excellent covers for political gerrymandering. The best way to guarantee fair maps is to stick to measurable criteria.

For instance we developed measurable criteria based on Census stats to define urban metro areas (see the Urban County Cluster sticky thread). I haven't seen a good way to specify an item like cultural areas that isn't open to abuse by subjectivity.

My approach to redistricting is a British one.
I have for a long time taken a significant interest in British Boundary Reviews and have made multiple submissions to reviews.
The British boundary reviews currently have only one requirement, and that is that constituencies must be within quota, other than that there are no steadfast rules, only guidelines and aims, yet despite this the British system works perfectly well, free of gerrymandering.
In Australia we use the British system. The Redistribution Committee do not aim, when conducting redistributions, to split as few local government areas as physically possible. Their aim is for minimum change, while simultaneously keeping communities of interest together and maintaining compact and logical districts.
There is no gerrymandering in the UK or Australia. In Australia we did have had the Playmander in SA and the Bjelkemander in Queensland, however neither of these were gerrymanders, they were egregious cases of Malapportionment. The electoral districts were not gerrymandered, they were still logical and compact, the problem was that rural districts were far smaller than urban districts, in some cases being only a tenth of the size of the urban districts.

[AustralianSwingVoter]

Holy hell is that a lot of cut counties - I have drawn maps that only cut 6.

No it isn't, only 16 counties were split between two or more congressional districts, and with 3 being larger than a congressional district, that leaves but 13 counties split.
Also, I don't draw my maps with the sole objective of splitting as few counties as possible, I also take into account urban areas, statistical areas, cultural regions, existing districts and many other factors.

Counties are very important as political units, and except in New England probably the most important unit in the US. It is one of the most common items to protect for states that have rules against gerrymandering.

Most certainly, I completely agree with you, however, as I said, I don't think the sole metric of a fair redistricting plan is that it splits as few counties as possible, yes that is a key metric, however it shouldn't be the only aim of redistricting.

The problem I have observed is that some criteria that sound good actually are quite subjective. These criteria are excellent covers for political gerrymandering. The best way to guarantee fair maps is to stick to measurable criteria.

For instance we developed measurable criteria based on Census stats to define urban metro areas (see the Urban County Cluster sticky thread). I haven't seen a good way to specify an item like cultural areas that isn't open to abuse by subjectivity.

My approach to redistricting is a British one.
I have for a long time taken a significant interest in British Boundary Reviews and have made multiple submissions to reviews.
The British boundary reviews currently have only one requirement, and that is that constituencies must be within quota, other than that there are no steadfast rules, only guidelines and aims, yet despite this the British system works perfectly well, free of gerrymandering.
In Australia we use the British system. The Redistribution Committee do not aim, when conducting redistributions, to split as few local government areas as physically possible. Their aim is for minimum change, while simultaneously keeping communities of interest together and maintaining compact and logical districts.
There is no gerrymandering in the UK or Australia. In Australia we did have had the Playmander in SA and the Bjelkemander in Queensland, however neither of these were gerrymanders, they were egregious cases of Malapportionment. The electoral districts were not gerrymandered, they were still logical and compact, the problem was that rural districts were far smaller than urban districts, in some cases being only a tenth of the size of the urban districts.

Unfortunately, even some independent panels in the US have suffered from subjective biases. I'm a fan of the method IA uses where the criteria are well defined in statute and an independent body draws the map based on the criteria.

Iowa is good by American standards but it isn't really that good compared to the rest of the world. In fact it's a great example of my point. The Des Moines urban area is split between all four congressional districts, while if you just split a single county then all of Des Moines could be united in one single congressional district. In the same vein Western Iowa is also split between two districts, when it could easily be united as one.

[AustralianSwingVoter]

For instance we developed measurable criteria based on Census stats to define urban metro areas (see the Urban County Cluster sticky thread). I haven't seen a good way to specify an item like cultural areas that isn't open to abuse by subjectivity.

Communities of interest should be identified now for use following the 2020 Census. This would permit objective criteria to be proposed and evaluated. Otherwise you have people playing hocus pocus with the redistricting commission.

You must be logged in to read this quote.

Most of the census data that could be used is from the ACS. The Census Bureau will do special tabulations of the ACS for those willing to pay for it. Race or ethnicity is a social interest. I suspect they deliberately avoided it as an example.

Communities of interest overlap and constantly change. That is why you shouldn't just draw a map and use it just like that. You need to develop a plan, then consult with local communities, then improve or change the plan, then consult again, and so on.

For instance in the UK they develop then publish the Initial Proposals, then there is an Initial Consultation period, with written representations and public hearings, then there is a Secondary Consultation period, with written representations and comments with regards to the written representations and public hearings of the Initial Consultation period, then, using the community input the proposals are then revised, and then published as the Revised Proposals (we are currently here), then there is a Final Consultation period with written representations, and then finally the proposals are further revised and then published as the Final Report which is then brought before Parliament to become law.

Meanwhile in Australia the process is even more thorough, with the timetable being:

Electoral Commission directs commencement of redistribution by way of Notice in the Commonwealth Government Notices Gazette.
Electoral Commissioner determines current enrolment quota Electoral Commission appoints Redistribution Committee.
Production and checking of enrolment projections.
The Electoral Commissioner invites written suggestions to the redistribution from the public.
Suggestions available for public to make written comments on suggestions.
Redistribution Committee considers suggestions and comments on suggestions and develops a set of boundary proposals.
Production of Redistribution Committee’s report and maps showing proposed names and boundaries.
Redistribution Committee publishes and exhibits maps showing proposed boundaries and names and reasons for proposal. Public invited to make written objections to the proposed redistribution.
Objections available for public to make written comments on objections.
Augmented Electoral Commission considers objections and comments on objections. As part of these considerations, a public inquiry into objections may be held.
Announcement of augmented Electoral Commission’s proposed redistribution.
Final determination of names and boundaries of electoral divisions by notice published in the Gazette.
Augmented Electoral Commission’s report tabled in Parliament.
Augmented Electoral Commission’s report is made publicly available.

[AustralianSwingVoter]

For instance we developed measurable criteria based on Census stats to define urban metro areas (see the Urban County Cluster sticky thread). I haven't seen a good way to specify an item like cultural areas that isn't open to abuse by subjectivity.

Communities of interest should be identified now for use following the 2020 Census. This would permit objective criteria to be proposed and evaluated. Otherwise you have people playing hocus pocus with the redistricting commission.

You must be logged in to read this quote.

Most of the census data that could be used is from the ACS. The Census Bureau will do special tabulations of the ACS for those willing to pay for it. Race or ethnicity is a social interest. I suspect they deliberately avoided it as an example.

Communities of interest overlap and constantly change. That is why you shouldn't just draw a map and use it just like that. You need to develop a plan, then consult with local communities, then improve or change the plan, then consult again, and so on.

For instance in the UK they develop then publish the Initial Proposals, then there is an Initial Consultation period, with written representations and public hearings, then there is a Secondary Consultation period, with written representations and comments with regards to the written representations and public hearings of the Initial Consultation period, then, using the community input the proposals are then revised, and then published as the Revised Proposals (we are currently here), then there is a Final Consultation period with written representations, and then finally the proposals are further revised and then published as the Final Report which is then brought before Parliament to become law.

Meanwhile in Australia the process is even more thorough, with the timetable being:

Electoral Commission directs commencement of redistribution by way of Notice in the Commonwealth Government Notices Gazette.
Electoral Commissioner determines current enrolment quota Electoral Commission appoints Redistribution Committee.
Production and checking of enrolment projections.
The Electoral Commissioner invites written suggestions to the redistribution from the public.
Suggestions available for public to make written comments on suggestions.
Redistribution Committee considers suggestions and comments on suggestions and develops a set of boundary proposals.
Production of Redistribution Committee’s report and maps showing proposed names and boundaries.
Redistribution Committee publishes and exhibits maps showing proposed boundaries and names and reasons for proposal. Public invited to make written objections to the proposed redistribution.
Objections available for public to make written comments on objections.
Augmented Electoral Commission considers objections and comments on objections. As part of these considerations, a public inquiry into objections may be held.
Announcement of augmented Electoral Commission’s proposed redistribution.
Final determination of names and boundaries of electoral divisions by notice published in the Gazette.
Augmented Electoral Commission’s report tabled in Parliament.
Augmented Electoral Commission’s report is made publicly available.

As jimrtex notes, the problem has often been identifying standards that justifies a community so as to achieve a political goal. In 2011 I sat though a great deal of public testimony of the kind that the UK and Oz require. I also watched the mapmakers cherry-pick which testimony to give weight, and then see them identify those favored groups.

Communities do change, but redistricting is once a decade at a very well-defined point in time. There's no reason not to quantify the communities  in advance of that set date.

I totally agree with you with regards to your second point. The best mapmakers can do is to use long term communities of interest and, key, using the communities of interest at the time of the redistricting, not the communities of interest from a couple of years ago. The best way to quantify communities of interest is to consult with the local communities. Communities of interest are a societal construct, they cannot be quantified in pure geographical terms, only in opinions.

[AustralianSwingVoter]

Iowa is good by American standards but it isn't really that good compared to the rest of the world. In fact it's a great example of my point. The Des Moines urban area is split between all four congressional districts, while if you just split a single county then all of Des Moines could be united in one single congressional district. In the same vein Western Iowa is also split between two districts, when it could easily be united as one.

"urban area" has a quite specific meaning in the United States census. You may be using some entirely different meaning. What is the name of that county that you believe if it were split would unify Des Moines in a single congressional district.

If western Iowa were in a single district, as it was during the 2000s, what would the other three look like? Some of the others during the 2000s were ugly.

Because I am to lazy to draw my own this very second I'll just borrow a map from Dailykos:

[AustralianSwingVoter]

Iowa is good by American standards but it isn't really that good compared to the rest of the world. In fact it's a great example of my point. The Des Moines urban area is split between all four congressional districts, while if you just split a single county then all of Des Moines could be united in one single congressional district. In the same vein Western Iowa is also split between two districts, when it could easily be united as one.

"urban area" has a quite specific meaning in the United States census. You may be using some entirely different meaning. What is the name of that county that you believe if it were split would unify Des Moines in a single congressional district.

If western Iowa were in a single district, as it was during the 2000s, what would the other three look like? Some of the others during the 2000s were ugly.

Because I am to lazy to draw my own this very second I'll just borrow a map from Dailykos:

Do you know what the PVI and deviation distribution is for this?

IMPORTANT REMINDER: THIS IS NOT MY MAP - IT IS FROM DAILYKOS
Here are statistics courtesy DailyKos

[AustralianSwingVoter]

Iowa is good by American standards but it isn't really that good compared to the rest of the world. In fact it's a great example of my point. The Des Moines urban area is split between all four congressional districts, while if you just split a single county then all of Des Moines could be united in one single congressional district. In the same vein Western Iowa is also split between two districts, when it could easily be united as one.

"urban area" has a quite specific meaning in the United States census. You may be using some entirely different meaning. What is the name of that county that you believe if it were split would unify Des Moines in a single congressional district.

If western Iowa were in a single district, as it was during the 2000s, what would the other three look like? Some of the others during the 2000s were ugly.

Because I am to lazy to draw my own this very second I'll just borrow a map from Dailykos:

Unfortunately for DK, IA has a very strict requirement to keep counties whole. The split county in this map does nothing to keep communities of interest whole. It does serve the political agenda of DK by packing the most conservative parts of the state into a single CD. This is what I mean by my concern over the lack of firm criteria; using soft standards invites subtle gerrymandering.

Of course this map could never happen without a change of law, however that law should, in my opinion, probably be changed (could you point me to the relevant statute, as I could see a problem in the law. The problem I see is what if one county is larger than a congressional district, of if one county is, lets say 25,000 people too small, yet all of the counties that border it have populations exceeding 50,000. It could, theoretically, happen in the future if Des Moines somehow becomes a thriving metropolis).
I cannot understand how you could think this plan doesn't improve communities of interest. It keeps all of Des Moines together, it keeps all of western Iowa together in one cohesive district.
Although Dailykos definitely decided on this map for political gain, doesn't mean this map isn't an improvement.

[AustralianSwingVoter]

Iowa is good by American standards but it isn't really that good compared to the rest of the world. In fact it's a great example of my point. The Des Moines urban area is split between all four congressional districts, while if you just split a single county then all of Des Moines could be united in one single congressional district. In the same vein Western Iowa is also split between two districts, when it could easily be united as one.

"urban area" has a quite specific meaning in the United States census. You may be using some entirely different meaning. What is the name of that county that you believe if it were split would unify Des Moines in a single congressional district.

If western Iowa were in a single district, as it was during the 2000s, what would the other three look like? Some of the others during the 2000s were ugly.

By urban area I am referring to three population groupings used by the US census bureau, called "Urban Areas", "Metropolitan Statistical Areas" and "Combined Statistical Areas"
The 2000 redistricting is probably the perfect example of my point. The congressional districts based on the 2000 census did not, in any way take into account compactness or communities of interest, the plan was merely the one with the smallest possible variation between the smallest and largest district, without splitting any counties.

[AustralianSwingVoter]

I will say again, Iowa has one of the best redistricting processes in the country in that it has no gerrymandering, nor the possibility of such. Any changes better be damn careful not to screw that up.

Although Iowa does not have gerrymandering, doesn't mean it's districts are particularly good.

[AustralianSwingVoter]

For a plan with N districts, there should not be more than N-1 county chops without a clearly definable reason. In a state like PA with lots of well defined cities, towns and Philly wards (identified by the names of the vote districts in DRA) there is no reason other than trying for exact population equality to chop any of them. Doing so divides a community of interest (less so with some of the wards). There are enough of those county subdivisions that it should always be possible to get within a relatively small deviation, probably under 1000 and certainly less than 0.5%.

The five Philly area counties plus Berks and Lancaster are a near perfect fit for 7 CDs with 2010 data. There should be no more than 6 chops in those counties, and this plan does that (3 chops in Philly, 1 each in Montco, Delco, and Chester. I don't know if towns and wards were preserved whole though, but I presume some minor adjustments could be made to respect those lines.

The county splits out west are a different matter. I know ASV said he thought the communities of interest are more important, but I'm not how that applies there. The western boundary of Cambria and Somerset counties is a significant mountain ridge that is largely protected by state forests. It seems that this plan tries to use the next, lower ridge to the west as the line separating communities of interest, but that doesn't comport with the actually lifestyle patterns in that part of the state from my visits. Those county lines in this case do a pretty good job of marking the separation between regions.

I think that PA-01 is a violation of any fair and reasonable map. Philadelphia has the population for at least two districts. I think that should require, in any fair map, that the city/county should have two districts within its boundaries. That does mean an additional chop of Chester, however I believe the preceding criteria should take precedence. And furthermore, I think the other problem with SEPA in that map is that PA-13 takes in two non-contiguous parts of Philadelphia.

Like I said, I don't think it's an overall unreasonable map apart from what I mentioned above. It just needs some cleaning up in terms of county splits. I would work on it myself, but I don't want to start from scratch. To start, I would swap numbering between PA-11 and PA-17 and I would make the new PA-11 a Lackawanna/Luzerne/Monroe district.

There is a school of thought that says one redistricting principle should be: In any county greater than the population for a whole district there should be a number of districts completely within the county equal to the population of the county divided by the quota for one district, rounded down to the nearest whole number. In PA that would require 2 CDs in wholly in Philly, 1 wholly in Montco, and 1 wholly in Allegheny.

We debated the merits of this principle on threads on this board back in 2012-13. In the end the majority view here was that a count of the total number of chops was a more important principle than considering how the fragments of the chops nested within counties. I shared that view in part from my experience in the 2011 OH Redistricting Competition, which had nesting requirements for legislative districts and rules that created a preference for wholly-contained districts in the congressional plan. I thought it created unneeded skews to other measures of the plan.

PA-1 and 2 could be entirely within Philly County, however I should have made it clearer that the arrangement exists solely to allow for 2 Black Majority congressional districts in Philly.

[AustralianSwingVoter]

For a plan with N districts, there should not be more than N-1 county chops without a clearly definable reason. In a state like PA with lots of well defined cities, towns and Philly wards (identified by the names of the vote districts in DRA) there is no reason other than trying for exact population equality to chop any of them. Doing so divides a community of interest (less so with some of the wards). There are enough of those county subdivisions that it should always be possible to get within a relatively small deviation, probably under 1000 and certainly less than 0.5%.

The five Philly area counties plus Berks and Lancaster are a near perfect fit for 7 CDs with 2010 data. There should be no more than 6 chops in those counties, and this plan does that (3 chops in Philly, 1 each in Montco, Delco, and Chester. I don't know if towns and wards were preserved whole though, but I presume some minor adjustments could be made to respect those lines.

The county splits out west are a different matter. I know ASV said he thought the communities of interest are more important, but I'm not how that applies there. The western boundary of Cambria and Somerset counties is a significant mountain ridge that is largely protected by state forests. It seems that this plan tries to use the next, lower ridge to the west as the line separating communities of interest, but that doesn't comport with the actually lifestyle patterns in that part of the state from my visits. Those county lines in this case do a pretty good job of marking the separation between regions.

I think that PA-01 is a violation of any fair and reasonable map. Philadelphia has the population for at least two districts. I think that should require, in any fair map, that the city/county should have two districts within its boundaries. That does mean an additional chop of Chester, however I believe the preceding criteria should take precedence. And furthermore, I think the other problem with SEPA in that map is that PA-13 takes in two non-contiguous parts of Philadelphia.

Like I said, I don't think it's an overall unreasonable map apart from what I mentioned above. It just needs some cleaning up in terms of county splits. I would work on it myself, but I don't want to start from scratch. To start, I would swap numbering between PA-11 and PA-17 and I would make the new PA-11 a Lackawanna/Luzerne/Monroe district.

There is a school of thought that says one redistricting principle should be: In any county greater than the population for a whole district there should be a number of districts completely within the county equal to the population of the county divided by the quota for one district, rounded down to the nearest whole number. In PA that would require 2 CDs in wholly in Philly, 1 wholly in Montco, and 1 wholly in Allegheny.

We debated the merits of this principle on threads on this board back in 2012-13. In the end the majority view here was that a count of the total number of chops was a more important principle than considering how the fragments of the chops nested within counties. I shared that view in part from my experience in the 2011 OH Redistricting Competition, which had nesting requirements for legislative districts and rules that created a preference for wholly-contained districts in the congressional plan. I thought it created unneeded skews to other measures of the plan.

PA-1 and 2 could be entirely within Philly County, however I should have made it clearer that the arrangement exists solely to allow for 2 Black Majority congressional districts in Philly.

The 2010 Census had 665K blacks (including Hispanic blacks) in the city of Philadelphia. The 2010 Census set a quota of 706K per CD. The black population in Philly isn't large enough to be the majority in 2 CDs.

That is why the 1st congressional district ventures into Delaware County, so that, on DRA figures:

District 1 D+36.23 - 86.0 - 13.5 - 50.5 African American
District 2 D+40.09 - 89.4 - 10.2 - 50.1 African American

[AustralianSwingVoter]

For a plan with N districts, there should not be more than N-1 county chops without a clearly definable reason. In a state like PA with lots of well defined cities, towns and Philly wards (identified by the names of the vote districts in DRA) there is no reason other than trying for exact population equality to chop any of them. Doing so divides a community of interest (less so with some of the wards). There are enough of those county subdivisions that it should always be possible to get within a relatively small deviation, probably under 1000 and certainly less than 0.5%.

The five Philly area counties plus Berks and Lancaster are a near perfect fit for 7 CDs with 2010 data. There should be no more than 6 chops in those counties, and this plan does that (3 chops in Philly, 1 each in Montco, Delco, and Chester. I don't know if towns and wards were preserved whole though, but I presume some minor adjustments could be made to respect those lines.

The county splits out west are a different matter. I know ASV said he thought the communities of interest are more important, but I'm not how that applies there. The western boundary of Cambria and Somerset counties is a significant mountain ridge that is largely protected by state forests. It seems that this plan tries to use the next, lower ridge to the west as the line separating communities of interest, but that doesn't comport with the actually lifestyle patterns in that part of the state from my visits. Those county lines in this case do a pretty good job of marking the separation between regions.

I think that PA-01 is a violation of any fair and reasonable map. Philadelphia has the population for at least two districts. I think that should require, in any fair map, that the city/county should have two districts within its boundaries. That does mean an additional chop of Chester, however I believe the preceding criteria should take precedence. And furthermore, I think the other problem with SEPA in that map is that PA-13 takes in two non-contiguous parts of Philadelphia.

Like I said, I don't think it's an overall unreasonable map apart from what I mentioned above. It just needs some cleaning up in terms of county splits. I would work on it myself, but I don't want to start from scratch. To start, I would swap numbering between PA-11 and PA-17 and I would make the new PA-11 a Lackawanna/Luzerne/Monroe district.

There is a school of thought that says one redistricting principle should be: In any county greater than the population for a whole district there should be a number of districts completely within the county equal to the population of the county divided by the quota for one district, rounded down to the nearest whole number. In PA that would require 2 CDs in wholly in Philly, 1 wholly in Montco, and 1 wholly in Allegheny.

We debated the merits of this principle on threads on this board back in 2012-13. In the end the majority view here was that a count of the total number of chops was a more important principle than considering how the fragments of the chops nested within counties. I shared that view in part from my experience in the 2011 OH Redistricting Competition, which had nesting requirements for legislative districts and rules that created a preference for wholly-contained districts in the congressional plan. I thought it created unneeded skews to other measures of the plan.

PA-1 and 2 could be entirely within Philly County, however I should have made it clearer that the arrangement exists solely to allow for 2 Black Majority congressional districts in Philly.

The 2010 Census had 665K blacks (including Hispanic blacks) in the city of Philadelphia. The 2010 Census set a quota of 706K per CD. The black population in Philly isn't large enough to be the majority in 2 CDs.

That is why the 1st congressional district ventures into Delaware County, so that, on DRA figures:

District 1 D+36.23 - 86.0 - 13.5 - 50.5 African American
District 2 D+40.09 - 89.4 - 10.2 - 50.1 African American

Is that black population or black VAP? The latter is what counts in determining if it is majority black.

It's whatever DRA gives as African-American

[AustralianSwingVoter]

For a plan with N districts, there should not be more than N-1 county chops without a clearly definable reason. In a state like PA with lots of well defined cities, towns and Philly wards (identified by the names of the vote districts in DRA) there is no reason other than trying for exact population equality to chop any of them. Doing so divides a community of interest (less so with some of the wards). There are enough of those county subdivisions that it should always be possible to get within a relatively small deviation, probably under 1000 and certainly less than 0.5%.

The five Philly area counties plus Berks and Lancaster are a near perfect fit for 7 CDs with 2010 data. There should be no more than 6 chops in those counties, and this plan does that (3 chops in Philly, 1 each in Montco, Delco, and Chester. I don't know if towns and wards were preserved whole though, but I presume some minor adjustments could be made to respect those lines.

The county splits out west are a different matter. I know ASV said he thought the communities of interest are more important, but I'm not how that applies there. The western boundary of Cambria and Somerset counties is a significant mountain ridge that is largely protected by state forests. It seems that this plan tries to use the next, lower ridge to the west as the line separating communities of interest, but that doesn't comport with the actually lifestyle patterns in that part of the state from my visits. Those county lines in this case do a pretty good job of marking the separation between regions.

I think that PA-01 is a violation of any fair and reasonable map. Philadelphia has the population for at least two districts. I think that should require, in any fair map, that the city/county should have two districts within its boundaries. That does mean an additional chop of Chester, however I believe the preceding criteria should take precedence. And furthermore, I think the other problem with SEPA in that map is that PA-13 takes in two non-contiguous parts of Philadelphia.

Like I said, I don't think it's an overall unreasonable map apart from what I mentioned above. It just needs some cleaning up in terms of county splits. I would work on it myself, but I don't want to start from scratch. To start, I would swap numbering between PA-11 and PA-17 and I would make the new PA-11 a Lackawanna/Luzerne/Monroe district.

There is a school of thought that says one redistricting principle should be: In any county greater than the population for a whole district there should be a number of districts completely within the county equal to the population of the county divided by the quota for one district, rounded down to the nearest whole number. In PA that would require 2 CDs in wholly in Philly, 1 wholly in Montco, and 1 wholly in Allegheny.

We debated the merits of this principle on threads on this board back in 2012-13. In the end the majority view here was that a count of the total number of chops was a more important principle than considering how the fragments of the chops nested within counties. I shared that view in part from my experience in the 2011 OH Redistricting Competition, which had nesting requirements for legislative districts and rules that created a preference for wholly-contained districts in the congressional plan. I thought it created unneeded skews to other measures of the plan.

PA-1 and 2 could be entirely within Philly County, however I should have made it clearer that the arrangement exists solely to allow for 2 Black Majority congressional districts in Philly.

The 2010 Census had 665K blacks (including Hispanic blacks) in the city of Philadelphia. The 2010 Census set a quota of 706K per CD. The black population in Philly isn't large enough to be the majority in 2 CDs.

That is why the 1st congressional district ventures into Delaware County, so that, on DRA figures:

District 1 D+36.23 - 86.0 - 13.5 - 50.5 African American
District 2 D+40.09 - 89.4 - 10.2 - 50.1 African American

Is that black population or black VAP? The latter is what counts in determining if it is majority black.

It's whatever DRA gives as African-American

It gives two different boxes for demographics. The upper box is for the whole population. Back around 2010, I pointed out to DRA that the voting age population (VAP) is what the courts look at to determine the minority strength, and they added a second box below the first. It's the percentages in the second box that matter.

I always tick all the don't show boxes, after looking just now it seems that I have been ticking the box, however as DRA already crashes my computer quite frequently I don't want to have to be on my knees screaming to the heavens "NOOOOO, WHYYYYY" any more than I already have to. Remember, I'm doing it on a MacBook Air with 50 chrome tabs always open. I've already had to have my battery replaced twice when the first should be good until 2019.