Pennsylvania's hotly contested Senate race hangs in the balance nearly a week after Election Day, with Republicans declaring victory and Democrats holding out hope that the remaining batch of outstanding ballots will allow them to close the gap.
NBC News has yet to project a winner in the contest between Democratic Sen. Bob Casey and Republican Dave McCormick, who are separated by just over 40,000 votes with 98% of the expected vote in. An estimated 122,000 ballots have yet to be tallied.
McCormick declared victory Thursday after The Associated Press called the race in his favor. Since then, he and his GOP allies in Washington have ramped up the pressure on Casey to concede, arguing he has no path to victory.
"The AP called this race a number of days ago because mathematically, there's no path for Sen. Casey to win," McCormick said in a Fox News interview Sunday.
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"Ultimately, Sen. Casey's going to have to decide when he's ready to acknowledge that," he added.
The Casey campaign has argued the remaining number of expected provisional ballots, particularly from places like Philadelphia and the surrounding suburbs, could tilt the scales in its favor.
Maddy McDaniel, a spokesperson for Casey, who is in his third term, said in a statement Saturday that every day counties "are confirming there are more ballots that need to be counted."
"Pennsylvanians deserve to have their voices heard, and as state officials have made clear, counties across Pennsylvania need more time to tabulate remaining votes," she said.
A McCormick victory would further pad Republicans' newfound majority in the Senate, where they will hold at least 52 seats after the election. The size of the majority could play an important role in how much of President-elect Donald Trump's agenda will pass and how many of his nominees will get confirmed.
But even before the new Congress is sworn in next January, the outcome of the Pennsylvania race could have implications for the Senate leadership elections Wednesday.
Three Republicans are vying to replace Sen. Mitch McConnell of Kentucky as the party's leader, and senators-elect can participate in the vote.
Without a clear winner yet in Pennsylvania, though, Senate Majority Leader Chuck Schumer, D-N.Y., is waiting to invite either McCormick or Casey to Congress this week for orientation and Wednesday's vote — a move that has angered Republicans.
Sen. John Thune of South Dakota, who is running to be the GOP leader, said on X that “the idea that Schumer would not allow him to participate in Senate orientation is beyond unacceptable.”
Sen. Tom Cotton, R-Ark., called Schumer's move to hold off on inviting McCormick a "shameful, election-denying decision" in a post on X.
A Schumer spokesperson defended the decision, pointing to the number of ballots that have yet to be counted in Pennsylvania.
"With over 100,000 ballots left to be counted in Pennsylvania, the race has not been decided," spokesperson Alex Nguyen said. "As is custom, we will invite the winner once the votes are counted."
Similarly, Arizona Democratic Senate candidate Ruben Gallego was also not invited to the orientation as his race against Republican Kari Lake is too close to call, according to an NBC News projection. He leads by 2 percentage points with 91% of the expected vote in.
Provisional ballots were a contentious issue in Pennsylvania even before Election Day. Pennsylvanians can cast provisional ballots when officials are unclear about their eligibility or there were issues with their returned mail-in ballots. In the days after an election, officials work to determine whether such voters are eligible to cast ballots, and if they are, their votes will be counted.
In the days before Election Day, the U.S. Supreme Court ruled to allow Pennsylvania voters who sent mail ballots that were flagged as potentially defective to submit separate provisional in-person ballots, rejecting a lawsuit from Republicans.
McCormick’s campaign filed two lawsuits Friday challenging an estimated 15,000 to 20,000 provisional ballots in Philadelphia that may have issues, such as missing signatures. Philadelphia is a deep-blue area, and the results in the county so far have leaned heavily in Casey’s favor.
The court dismissed the issue for the time being.
As of Sunday, the Casey campaign was still expressing optimism about overcoming its vote deficit, pointing to the roughly 76% of provisional ballots that favored Democrat John Fetterman over Republican Mehmet Oz in 2022.
"We don’t believe we need to reach Fetterman’s percent breakdown in order to win. What’s more, there are thousands of ballots that are supportive of Casey that are being cured," said a person close to the Casey campaign, referring to the processing of addressing minor mistakes on mail ballots, such as signature issues.
At the presidential level, NBC News projected that Trump won Pennsylvania. He leads Vice President Kamala Harris by about 2 percentage points.
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