100 Senate Seats by population

[Torie]

It turns out CA is quite well suited to 10 districts. Things turned out quite nicely.

No, I don't know the partisan divisions. I turned off the partisan numbers to reduce the size of the file, to keep the program from crashing. Four of the districts are clearly safe Dem, with the Riverside-San Bernadino-Imperial CD probably strong lean Dem (the Pub parts of Riverside are mostly not in it), the San Diego based district competitive, the Orange County based district lean Pub, the Santa Barbara-Ventura-Antelope Valley-Kern County district competitive (it has some Democratic areas of the San Fernando Valley to offset Kern's Pub margins), the Sacramento based district probably lean Dem (Sacramento and San Joaquin probably more than offset the Pub areas), and the southern Central Valley-Sierra district perhaps lean Pub, or maybe competitive (it has hyper Dem Santa Cruz and Dem Monterey County in it to offset much of the Pub areas).

The San Gabriel based district is 58.7% HVAP, the Riverside-San Bernadino district 45.5% HVAP, the southern Central Valley district 40.5% HVAP, and the Kern-Ventura-Santa Barbara-Antelope Valley district 40.4% HVAP. Given the huge size of the districts, other than the San Gabriel Valley district, with a contiguous Hispanic zone, I don't think the VRA really applies.

[Torie]

The arbitrary county chops in IL make no sense except to create marginally straight lines. Given the large populations there's no reason to chop any county except Cook. In chopping Cook more weight should be given to minority interests.

This plan maintains townships in Cook and neighborhoods in Chicago. It creates a strong minority district with a plurality Black population that is only about a third white. By linking the north side of Cook with Lake and Kane the large Hispanic populations in suburban Aurora, Elgin, and Waukegan are grouped together.

Politically the Cook districts are both strong D, the remaining suburban-NW IL district is lean R and the downstate district is strong R.

It looks like you've chopped the city of Chicago, which gives it outsized influence in two districts instead of just the one that it deserves.

Because in Cook it isn't just about Chicago, but about minority representation. With the large black population and significant Latino population, a cut where I placed it makes a BVAP plurality. If Chicago is kept whole, it's a white plurality.

To keep whole counties, I would also have to chop Chicago to put O'Hare airport with non-Chicago Cook. It's not big, but it is a chop.

Except that the VRA does not apply to plurality districts, and Illinois does not have a Florida type law, so you are making a political-policy choice here.

[Torie]

Except that the VRA does not apply to plurality districts, and Illinois does not have a Florida type law, so you are making a political-policy choice here.

Well, you split Los Angeles into 3 districts for no apparent reason, too.  

I dissent from the party line that counties need to be kept whole but cities do not - especially where city boundaries cross county lines.  I think incorporated cities should be kept whole first, to avoid the largest cities from having undue influence over the rest of the state. People have more allegiance to their city than their county, anyway.  

The part of Chicago in DuPage County has little to no population, anyway, so putting O'Hare in a Chicago-only district would be a microchop of a county at best- and utterly meaningless if the few people who used to live near the airport in DuPage Chicago have been moved due to the runway reconfiguration project, anyway.  Who cares if boundaries cross county lines to keep a city intact if nobody lives there?

It's impossible to keep LA City whole due to its shape going down to the harbor, and trapping the coastal cities. Even without the trapping issue, the city in 2010 has about 200,000 too many people to be all in one district anyway. In addition, the VRA drives the Hispanic San Gabriel Valley district, and it needs to take in some of LA City to get to a high enough Hispanic percentage, and that is certainly the case if one wants to avoid an erose mess. Otherwise I would not have done that chop, because I am sensitive to tri-chopping anything, including a city. Counties rule over cities in the metric that Muon2 and I set up, and in addition, putting aside the VRA, there should be but one muni chop between districts. Your mileage varies, which is fine. Different strokes for different folks.

I might add that the Kern-Santa Barbara-Ventura district has about 27% of its population in LA city, so the city is hardly dominating. The Hispanic San Gabriel Valley based district has about 19% of its population in the city.

[Torie]

Except that the VRA does not apply to plurality districts, and Illinois does not have a Florida type law, so you are making a political-policy choice here.

Well, you split Los Angeles into 3 districts for no apparent reason, too.  

I dissent from the party line that counties need to be kept whole but cities do not - especially where city boundaries cross county lines.  I think incorporated cities should be kept whole first, to avoid the largest cities from having undue influence over the rest of the state. People have more allegiance to their city than their county, anyway.  

The part of Chicago in DuPage County has little to no population, anyway, so putting O'Hare in a Chicago-only district would be a microchop of a county at best- and utterly meaningless if the few people who used to live near the airport in DuPage Chicago have been moved due to the runway reconfiguration project, anyway.  Who cares if boundaries cross county lines to keep a city intact if nobody lives there?

It's impossible to keep LA City whole due to its shape going down to the harbor, and trapping the coastal cities. Even without the trapping issue, the city in 2010 has about 200,000 too many people to be all in one district anyway. In addition, the VRA drives the Hispanic San Gabriel Valley district, and it needs to take in some of LA City to get to a high enough Hispanic percentage, and that is certainly the case if one wants to avoid an erose mess. Otherwise I would not have done that chop, because I am sensitive to tri-chopping anything, including a city. Counties rule over cities in the metric that Muon2 and I set up, and in addition, putting aside the VRA, there should be but one muni chop between districts. Your mileage varies, which is fine. Different strokes for different folks.

I might add that the Kern-Santa Barbara-Ventura district has about 27% of its population in LA city, so the city is hardly dominating. The Hispanic San Gabriel Valley based district has about 19% of its population in the city.

I think you should put Compton and Carson in the OC district, then you could move the LA boundary east and the San Gabriel district south.

Also, I would swap Contra Costa and San Mateo.

That would reduce the chop by the San Gabriel district into LA City (but not eliminate it), and would reduce the Hispanic percentage to perhaps unacceptably low numbers, and make the the OC district more erose, without having much impact on the westside LA City dominated district.

Here is a CA  version incorporating Jimrtex’s idea about the split of the Bay area. Half dozen one way or the other whether chopping San Mateo or Contra Costa is best in my view. There are plusses and minuses to each. As to Jimrtex's second suggestion, putting Carson in the OC district works OK, but not Compton, because it generates an ugly municipal chop. In addition, this map has the partisan skew right, per Muon2’s methodology, so the OC district cannot fall below 1.5% Pub PVI, and if it did, I would have Pubbed it up to get it back up. Thus Compton needs to stay out in all events, and arguably Carson too, but I will let it go since the 1.5% hurdle was met. I have no doubt that my CA-05 is more Dem now than it was in 2008, so it is now clearly a Dem lean district, in a way that the OC district might not be going the other way (the OC district overall probably has not trended much since 2008 overall). CA-07 cannot fall below 58% HVAP, so its lines into LA City as drawn are close to mandatory unless one wants to get considerably more ugly and erose. Nothing else quite gets there, although perhaps by now, the district might be up to 60% HVAP.

It's interesting that 9 of the 10 districts have more Asians than blacks. Is there any state in the US other than Hawaii that has more Asians than blacks at this point? Maybe in Washington and Oregon?