Live Results: Pennsylvania U.S. Senate race

The polls have officially closed after Pennsylvania voters cast their ballots for president and several key races across the state, including a high-stakes U.S. Senate contest.

Polling locations across Pennsylvania were open from 7 a.m. to 8 p.m. on Election Day as residents decided to elect either incumbent U.S. Senator Bob Casey, or his Republican opponent, Dave McCormick.

A win for either candidate could help determine which party controls the narrowly divided Senate.

Casey and McCormick appeared on ballots Tuesday along with five other candidates who were vying for Pennsylvania's U.S. Senate seat. Casey, whose website describes him as "a voice for middle-class families, workers, and seniors," has won his last three re-election bids since he first won a U.S. Senate seat in 2006.

Incumbent Bob Casey (D) faced off with Dave McCormick for Pennsylvania's U.S. Senate Seat Tuesday. (Getty Images) 

Meanwhile, McCormick has never held a political office and lost the 2022 Pennsylvania Republican primary for U.S. Senate to Dr. Mehmet Oz, who ultimately lost to John Fetterman. 

Still, the Associated Press called McCormick's campaign "the strongest challenge to Casey in his three reelection bids."

The contentious race tightened ahead of Election Day as both campaigns launched broadsides on televisions across the state, and traded jabs in energetic debates.

Both candidates disagreed on key issues for voters, including abortion rights, gun laws and clean energy policy.