Democratic Congresswoman Lauren Underwood has clinched another term representing Illinois’ 14th Congressional District in the far western suburbs, but her Republican challenger is refusing to concede.

The Associated Press called the race Thursday afternoon for Underwood, a freshman representative who garnered 50.5% of the vote over her challenger, Republican State Sen. Jim Oberweis, of Sugar Grove. The two are separated by just 4,288 votes, as mail-in ballots continue to be tallied.

“I am honored to be reelected to represent Illinois’ beautiful 14th District in Congress,” Underwood said in a statement. “This was a tough race under some very difficult circumstances, and I want to say thank you to my supporters, the voters, and our elections officials for their diligent work.”

When asked whether Oberweis was planning to concede, the GOP candidate’s campaign manager said “not at all” shortly after The Associated Press called the race for Underwood. Earlier in the week, spokesperson Travis Akin told WBEZ a recount was imminent.

In a written statement, Akin said the campaign is “committed to exploring all legal options,” and that the Associated Press’ call “does not change anything in this race from a legal standpoint,” saying there are still votes that have yet to be counted and certified.

In Illinois, a candidate can request a recount if they’ve garnered 95% of the votes that the winning candidate received.

Oberweis initially claimed victory the day after last Tuesday’s election, when he was up by just 895 votes, saying the race was an “uphill battle.” His campaign has remained confident he’d win, despite Underwood encroaching and then taking the lead as more mail-in ballots have been tallied.

Underwood, 34, was swept into Congress during the 2018 blue wave that was largely seen as a reaction to discontent with GOP President Donald Trump. Previously a nurse, Underwood is a staunch supporter of the Affordable Care Act and is best known for her work passing the Lower Insulin Costs Now Act, which lowered the cost of the diabetes medication.

Her campaign focused on highlighting the need for a comprehensive approach to combating the pandemic and painted her as a bipartisan legislator, touting her record of getting four bills signed into law by Trump.

Oberweis, 74, has served in the Illinois General Assembly since 2013, representing the state’s 25th district. In addition to his many runs for office as a conservative, free-market candidate, Oberweis is best known as chairman of his family business, Oberweis Dairy.

His campaign platform focused on border security and limited government spending, and railed against the spread of “socialist ideas” like “wealth redistribution” and “job-killing tax plans.” Oberweis contended Underwood is too progressive for the district and votes with House Speaker Nancy Pelosi too often.

The 14th District leans conservative, but has become a congressional battleground, especially since Underwood’s stunning 2018 upset when she beat four-term Republican incumbent Randy Hultgren. This year’s race has been closely watched nationally as a determining factor in who controls a 2021 Congress.

Underwood’s victory represents a potentially shifting demographic in the mostly white, conservative district that was created after the 2010 census.

Mariah Woelfel is a general assignment reporter at WBEZ. Follow her on Twitter @MariahWoelfel.