OMG! Illinois has large demographics of Liberals and/or Independents outside of Chicago. All you have to do is examine an Election Map from 2012. Heavily populated St. Clair Co., across the river from St. Louis, is an example. Peoria Co. Is another. Champaign is another. In fact, most of Illinois' western border is Democrat. With the exception of Springfield, all of its metro areas are too. Yes, Cook County or Chicago is the largest concentration, but it's not alone. Southern, or "Conservative" IL, is a collection of rural farming counties (and not all of them are Republican). They are sparsely populated in comparison to larger, urban areas. They simply lack the votes to compete & Republicans know it. If the GOP wants to WIN a General Election, it needs to change its thinking, oust the Tea Party and earn votes! Instead, they sit on their backsides thinking of ways to split Districts, States, etc. To be honest, that only alienates voters. It doesn't attract them! What's next? Registering corn rows? Lincoln & Reagan MUST be rolling over in their graves!
Obama defeated Romney by 826,695 vote statewide in Illinois. He won Cook county by 959,919 votes. Without Cook county, Illinois would have leaned Romney. Give the proposed state of Chicago a few of the counties surrounding Cook, and the remainder of Illinois become redder than Indiana.
Indiana is a huge republican state. A county, Lake County, should join Chicago if it became a state. Lake County voted for Obama, not Romney. Lake County is a huge Union Worker place. They have Gary, with the mills.