All of those places you mentioned in Illinois DO vote Democratic except Bloomington.
The cities, not necessarily the metro areas. Part of rural Iowa in the Eastern part of the state is in that more liberal rural zone that includes western Wisconsin. It is not as liberal as the Birkenstock belt, but still unusual liberal for rural white areas. So that needs to be added to the mix.
The Quad Cities metro area definitely votes Democrat as a whole and is the most like an Iowa metro area. Iowa being often-blue has less to do with urbanized population and more to do with the culture of the Driftless Area. NW Illinois and SW Wisconsin vote similarly.
