The winner of Pennsylvania's U.S. Senate race still wasn't clear Wednesday night, and three House seats remained in limbo.

Republican challenger David McCormick has a roughly 31,000-vote lead over Democratic incumbent Bob Casey, which has been dwindling as outstanding votes continue to be counted. The roughly half-percentage-point margin between the candidates also qualifies the race for an automatic recount.

McCormick overtook Casey with about 80% of the estimated votes counted just before midnight on Tuesday. Casey initially had a lead over McCormick when just about 40% of the estimated votes had been counted, propelled in part by mailed ballots that have historically favored Democrats. McCormick was doing better in votes cast on Election Day.

House races

In all three of Pennsylvania's uncalled races, the Republican candidate held a slight lead, with some votes still outstanding and two Democrats conceding.

One uncalled race was the contest in an Allentown-based district in eastern Pennsylvania, where three-term Democratic U.S. Rep. Susan Wild conceded to Republican Ryan Mackenzie.

Mackenzie is a member of the state House of Representatives. Democrats hold a slight registration advantage in the district, but its close political divide made Wild a perennial target of Republicans.

Also uncalled was a race in a northeastern Pennsylvania district around Scranton and Wilkes-Barre, where six-term Democratic U.S. Rep. Matt Cartwright conceded to Republican Rob Bresnahan, a first-time candidate and developer who runs a family construction company.

Bresnahan claimed victory early Wednesday morning.

Democrats hold a slight registration advantage in the district, but voters there backed Trump in 2020’s presidential election, making Cartwright just one of five Democrats nationally running for reelection in a Trump district.

The other uncalled race is in southern Pennsylvania, where Republican Rep. Scott Perry is seeking a seventh term in his Republican-leaning district around the cities of Harrisburg and York.

Challenging him is Janelle Stelson, a longtime local TV news anchor who is a Republican-turned-Democrat.

Perry was chairman of the Freedom Caucus, a hardline faction of conservatives and was the only lawmaker to have his cellphone seized by FBI agents investigating the web of Trump loyalists who were central to his bid to remain in power in 2020. Perry has not been charged with a crime.

Elsewhere in Pennsylvania, 14 other incumbents were reelected.

Republicans are fighting to keep their slim majority in the chamber.

A House majority would give the GOP a full sweep of power in Congress alongside President-elect Donald Trump in the White House.