I grew up in Indiana, which is a typically Republican state, but I have lived in (the Peoples Republic of) Illinois since 1994. The state is dominated by Chicago and Crook County (i.e. Cook County, where Chicago ins located) in politics, even though downstate Illinois is much more like Indiana. In fact, there have been people here who have wanted to try to force the Chicago region to form a 51st state, distinct from Illinois, because they are so frustrated that the region dictates their liberal policies to the rest of the state. I sure wish this could happen. Here is a link with one story about that:

[governing.com]

@KeithThroop I have heard of some of these movements. I understand that for such a move to succeed, it would require the approval of the legislature of the state they are trying to separate from. If they did approve it, they would essentially be granting the other party at least three new federal lawmakers, and at least three more electoral college electors, and they would almost certainly lose some of their own. I can't imagine why a state legislature dominated by one party would agree to it, but I realize states have split in the past, so maybe I'm missing something.

@KeithThroop So I guess the best hope for Illinois turning red is for Chicago to experience a mass exodus that, one way or another, does not result in a net spread of blue dominance in the rest of the state. There appears to be an exodus in progress. It remains to be seen just how massive it will be and what the geopolitical implications will be.

@DaveO276 Well, people have actually been leaving the state at a pretty good clip for some time now, many of them conservatives sick of how things are here. The state has been driving businesses and citizens out with high taxes and bad policies. Here are a couple of articles about it:

[illinoispolicy.org]

[governing.com]