Illinois weighed in for this election as 5.4% more Democratic than the national average. Bush won the election in rapidly liberalizing Illinois with a narrow 2-point margin. Like the neighboring state of Missouri, Bush's performance here was far below that of President Ronald Reagan's just four years earlier. Bush's loss of many down-state rural counties, combined with Dukakis's stronger than normal performance across much of the state, especially in Cook County, which houses the Chicago area, made the election results in this state much closer than usual.
The presidential election of 1988 was a very partisan election for Illinois, with more than 99% of the electorate voting for either the Democratic or Republican parties, and only five political parties listed as options on the ballot statewide.[1] As of the 2024 presidential election, this was the last time that Illinois voted Republican in a presidential election. 1988 is also the most recent election in which Peoria County and Champaign County voted for a Republican presidential candidate, as well as the last time a Republican candidate won more than 40% of the vote in Cook County, home to Chicago.[2] This was the last time that Illinois was not the most Democratic state in the Midwest at the presidential level.