To illustrate the decisive shift the county has seen, in the 1984 presidential election, when incumbent President Ronald Reagan won re-election, he decisively won DuPage County with over three-quarters of the total vote, receiving 227,141 votes and a 75.66% share to Dukakis' meager 23.79% and 71,430 votes. As recently as the 2012 presidential election, DuPage County was still considered a swing county, which Obama won by barely a percentage point in his re-election. By the 2020 election, Joe Biden was able to carry DuPage County by a margin of 18.07% (one point greater than Hillary Clinton's 2016 win in the county) while garnering more than 281,000 votes, the most votes for a single presidential candidate in county history. In addition, then-incumbent president Donald Trump, in a high-turnout election, managed to garner nearly 35,000 less votes than Reagan did. Thus, in the 36 years since Reagan's landslide re-election, DuPage County has seen a net shift towards the Democratic Party by a margin of just under 70%.