Why did Illinois become so democratic?

[buritobr]

In a recent past, Illinois was not the most democratic state in the Midwest. In 1988, Bush had a narrow victory in Illinois, while Dukakis won Minnesotta, Wisconsin and Iowa. Nowadays, Illinois is the most democratic state in the Midwest, the difference is big. If a republican candidate have a big margin in the national popular vote, he will win all the Midwest, except Illinois.
What happened in the last 30 years?

[DabbingSanta]

Running up the margins in Chicago/Cook County and losing Republican support in surrounding suburbs. Cook voted +12 Dukakis vs +53 Biden. The MSA is also increasing in population — from 7.8 to 9.5 million people in thirty years.  In the 2010 gubernatorial election, Democratic candidate Pat Quinn won the election despite only winning the popular vote in four counties. All you need is around 70% in Cook and you can win the state.

[Clarko95 📚💰📈]

Cook County dominates Illinois to an extent that other major urban counties in the other states don't (e.g. Wayne, Milwaukee, Cuyahoga, Marion, etc.).

Furthermore, the demographic trends in the collar counties of Chicago continue to favor Democrats (higher education + more diverse). Finally, Cook County, while losing a large number of black voters, still attracts many young voters from around the Midwest and this also adds to Democratic margins.

I remember seeing a discussion somewhere about the Red Wall of 1968 - 1988, where heavily urban/suburban states like California, Illinois, New Jersey, and Connecticut voted GOP because of suburban moderates but from 1992 onwards defected to the Democratic Party in droves after the end of the Cold War and the rise of the culture wars.

[jamestroll]

You can't gain without losing. I fully expected IL to swing and trend GOP this year but surprising to still swung to Biden.

The fact that Kane and DuPage counties are the state median's now are now scary and show that downstate Illinois still has a large amount of voters and the GOP technically still has room to grow downstate but they are being hindered with the trends of McLean and Champaign counties and Sangamon to a lesser extent.

Kane voted slight to the right of Illinois and DuPage slightly to the left of Illinois all while there was obviously some backlash to Democrats over riots and lockdowns. Particularly in Illinois.

Going forward I could see the GOP getting like 44 to 45% in IL on a good night but the Chicagoland wall is a very tough nut to crack and it is hard to see Bruce Rauners and Mark Kirks breaking through again in the future because of that.

[Annatar]

Due to the dominance of Cook county, although this year Illinois is on track to only be D+12.6 in terms of partisan lean due to Trump's gains in Cook county assuming Biden wins nationally by 4.4% which will be its lowest democratic lean since 2000.

[buritobr]

After you told, I verified the population of states and counties

Illinois: 12.7M
Cook: 5.2M
Cook/Illinois: 41%

Wisconsin: 5.8M
Milwaukee: 0.9M
Dane: 0.5M
(Milwaukee+Dane)/Wisconsin: 24%

The share of the population of Illinois living in a county in which there is a big city is much bigger. It explains the fact that Illinois is much more democratic.

[TheElectoralBoobyPrize]

I just noticed that while Trump won the state outside Chicago both times (as did Romney, but not McCain), his margin this time was only about half what it was last time and may be reduced further by outstanding ballots.

[mileslunn]

Urban/rural split.  Historically that was much weaker, but as that has become stronger, since Illinois is considerably more urbanized than neighboring states, that made it much more Democratic.  2/3 of state's population live in Chicago metropolitan area while over 40% live in Cook County alone.  If you removed metropolitan areas over a million out of equation, Illinois would vote right of Wisconsin, Michigan, Iowa, and Minnesota while similar to Ohio and Indiana.

[Calthrina950]

I just noticed that while Trump won the state outside Chicago both times (as did Romney, but not McCain), his margin this time was only about half what it was last time and may be reduced further by outstanding ballots.

Biden flipped McLean and Kendall Counties and improved upon Clinton in the Collar Counties, becoming the first Democrat in recent times (and possibly ever) to break 60% in Lake County, to the north of Chicago. In other words, he improved in Outstate Illinois compared to Clinton, which is why his overall share of the vote was higher despite Trump's marginal improvement in Cook County.

[neostassenite31]

Would also add that it's not the relative size of Cook County as a percentage of Illinois that makes the state Democratic. It's more about how national Democrats routinely win Cook County by 50+ percentage points (see Clark County, Nevada for comparison)

[Buffalo Mayor Young Kim]

The suburbs basically.

In the 80s and even 90s the Chicago 'burbs, excepting a few of the working class outposts like Jolliette and Aurora, where extremely Republican, largely cancelling out Cook County. Elections were decided downstate.

Now that the collar counties are realiable Democratic votes, the GOP gets crushed.

[Hammy]

Chicago is the simplest single answer, but while Illinois would've gone R without Cook County, it's not like it would've suddenly become Indiana--it's only R+3. The state is better educated than surrounding states as well as having a larger pool of Dem voters in rural areas compared to Missouri, Indiana, or Ohio for example.

[TDAS04]

Because it is the most urban state in the Midwest, by far.

[cafaulait37]

Cook county. Enough said.

[Obama-Biden Democrat]

Would also add that it's not the relative size of Cook County as a percentage of Illinois that makes the state Democratic. It's more about how national Democrats routinely win Cook County by 50+ percentage points (see Clark County, Nevada for comparison)

The fact that Democrats can win a giant urban county like Clark, NV by only 10-15% is pathetic.

[buritobr]

Illinois was competitive when the democrats had <60% in Cook County. I think in the past, Chicago was democratic, but not so much like New York City, Boston, Philadelphia and San Francisco
https://en.wikipedia.org/wiki/Cook_County,_Illinois

[Sol]

Would also add that it's not the relative size of Cook County as a percentage of Illinois that makes the state Democratic. It's more about how national Democrats routinely win Cook County by 50+ percentage points (see Clark County, Nevada for comparison)

The fact that Democrats can win a giant urban county like Clark, NV by only 10-15% is pathetic.

Ehh, not really--Clark is basically all of the Las Vegas metro area (barring Pahrump, which is only sort of metro Las Vegas) plus some tumbleweeds. The equivalent would be considering all of Chicagoland, including the counties in Indiana.

[Sol]

Illinois was competitive when the democrats had <60% in Cook County. I think in the past, Chicago was democratic, but not so much like New York City, Boston, Philadelphia and San Francisco
https://en.wikipedia.org/wiki/Cook_County,_Illinois

Well, ofc Cook=/=Chicago--from what I understand Chicago has had urban Democratic machines for forever but in the past the suburbs were a counterbalance to the huge Dem margins there.

[TransfemmeGoreVidal]

Illinois was competitive when the democrats had <60% in Cook County. I think in the past, Chicago was democratic, but not so much like New York City, Boston, Philadelphia and San Francisco
https://en.wikipedia.org/wiki/Cook_County,_Illinois

Well, ofc Cook=/=Chicago--from what I understand Chicago has had urban Democratic machines for forever but in the past the suburbs were a counterbalance to the huge Dem margins there.

If anything Chicago was more Democratic then Philadelphia (which historically had a strong urban GOP machine) and New York where a lot of outer borough "white ethnics" were voting Republican as far back as Eisenhower and Nixon in 60.

[Alcibiades]

Illinois was competitive when the democrats had <60% in Cook County. I think in the past, Chicago was democratic, but not so much like New York City, Boston, Philadelphia and San Francisco
https://en.wikipedia.org/wiki/Cook_County,_Illinois

Well, ofc Cook=/=Chicago--from what I understand Chicago has had urban Democratic machines for forever but in the past the suburbs were a counterbalance to the huge Dem margins there.

Yeah, it’s just that Cook is pretty suburban compared to most other large urban counties. It was these inner Chicago suburbs flipping in the 90s/early 00s which initially turned the state Democratic.

[H. Ross Peron]

Would also add that it's not the relative size of Cook County as a percentage of Illinois that makes the state Democratic. It's more about how national Democrats routinely win Cook County by 50+ percentage points (see Clark County, Nevada for comparison)

The fact that Democrats can win a giant urban county like Clark, NV by only 10-15% is pathetic.

Ehh, not really--Clark is basically all of the Las Vegas metro area (barring Pahrump, which is only sort of metro Las Vegas) plus some tumbleweeds. The equivalent would be considering all of Chicagoland, including the counties in Indiana.

Not to mention Las Vegas's landscape is extremely suburban and exurban in character even compared to other metro areas. Hence why even Las Vegas city itself is much more Republican compared to most central cities.