I keep wondering why there is no “North” Illinois and “South” Illinois,makes no sense to me.They appear to be two different worlds.
There is the Chicago Metropolitan area (6 counties including Cook Country; all of Chicago is inside Cook) and then there is Downstate Illinois (everything else). There is also a rough stretch near St. Louis in the southwest part of Illinois that is much like Chicago. Making the 6-county portion its own state would separate the 2 worlds. And Missouri could keep the bad ST. Louis suburbs.
The new state could be called Lincoln. The only remaining problem with Lincoln would be removing Dick the Turban Durbin. I would contribute to that noble cause.
There are Northern and Southern Illinois Universities. Back in my day, Carbondale is where the hippies went.
If you take away Cook County (Chicago); and Madison County (St. Louis suburb county), Illinois would be a red state. In 2010, Republican Bill Brady from downstate Bloomington carried 98 of the 102 Illinois Counties and still lost the Governor race to Chicago Democrat Pat Quinn.