Southern Illinois
But in the last few decades, Southern Illinois has trended GOP due to the national support for them across rural areas. Northern Illinois has trended towards Democrats due to lots of that area's people leaving from  in and near the Democratic-leaning Cook County and nearby counties. Democratic candidates were fierce in the counties across Southern Illinois until around 1996. Beginning from the presidential election of 2000 on, Democratic officials weren't doing well like expected across Southern Illinois even if they had won almost very constantly.