Democrat Lauren Underwood succeeded in unseating Rep. Randy Hultgren (R), the four-term incumbent who has been in office since the 2010 tea party wave.
Underwood’s win in a district that has usually gone to Republicans may be critical for Democrats who need to gain 23 seats to flip the House.
Trump tweeted out a last minute push for Hultgren on Tuesday, saying the lawmaker was “doing a great job.”
Underwood, who was an adviser in the Department of Health and Human Services under the Obama administration, ran in part on a health-care agenda, targeting Hultgren for his vote to repeal and replace the Affordable Care Act.
The critical race saw a last-minute push from big names, including House Speaker Paul D. Ryan (R-Wis.), who visited the Chicago suburbs to rally for Hultgren last Friday. Former vice president Joe Biden stumped for Underwood, telling a St. Charles, Ill., crowd that “the very character of our country, of who we are, is on the ballot.”
The suburban Chicago district is one of many similar battlegrounds nationwide where Republicans are vulnerable because of President Trump’s low popularity. Democrats hoping to recapture the House majority are looking to dozens of suburban districts nationwide to help them flip the chamber.