- Voters are deciding several key races, including a Republican Senate primary that features Dr. Mehmet Oz, hedge fund boss Dave McCormick and commentator Kathy Barnette.
- Lt. Gov. John Fetterman will win the state's Democratic Senate primary race, NBC News projected.
- Republican state Sen. Doug Mastriano will compete against Democratic state Attorney General Josh Shapiro in the Pennsylvania gubernatorial election, NBC projected.
The top two candidates in Pennsylvania's neck-and-neck Republican Senate primary race said they don't expect a winner to be declared on election night.
"So, we're not going to have a result tonight," said Dr. Mehmet Oz, the celebrity physician endorsed in the race by former President Donald Trump.
"Get some rest," Oz told supporters at his election watch party. "When all the votes are tallied, I am confident we will win."
Dave McCormick, a former hedge fund CEO and the other top contender in the race, explained to his own supporters that thousands of mail-in ballots still needed to be counted.
"Unfortunately, we're not going to have resolution tonight. But we can see the path ahead. We can see victory ahead, and it's all because of you," McCormick said.
The two candidates were separated by a few hundred votes just after midnight.
The Pennsylvania Department of State confirmed the delay in results, attributing the lag to the fact that the state's laws do not permit "pre-canvassing" of ballots prior to Election Day. That means counties could only start counting those mail ballots on Tuesday morning, Acting Secretary of State Leigh Chapman said in a press release.
She noted that about 900,000 mail ballot applications were sent in for the primary, and said she expects the bulk of those ballots to be counted "within a few days."
The picture on the Democratic side of the primary was much clearer: NBC News projected that Pennsylvania Lt. Gov. John Fetterman will win the state's Democratic Senate primary race.
Fetterman, who recently suffered a stroke that took him off the campaign trail, was the heavy favorite in the Democratic contest. He and the eventual Republican nominee will face off in a general election that could play a decisive role in which party controls the U.S. Senate after the midterms.
Battle lines for the Pennsylvania gubernatorial contest in November were also drawn Tuesday night, with NBC projecting that Republican state Sen. Doug Mastriano will compete against Democratic state Attorney General Josh Shapiro.
Mastriano, who has trumpeted false claims that the 2020 presidential election was stolen, was endorsed by Trump just three days before the primary. Shapiro ran unopposed for the Democratic nomination to replace current Democratic Gov. Tom Wolf, who is term-limited from running again.
Oz, the former host of "The Dr. Oz Show," made waves when he announced he would run as a Republican for the Senate seat being vacated by retiring GOP Sen. Pat Toomey. He received Trump's coveted endorsement, and his campaign has reportedly spent more than $12 million in the race on advertising alone.
But Oz, a first-time campaigner who has lived in New Jersey for two decades, was neck-and-neck in the polls with two other Republicans: McCormick, and right-wing commentator Kathy Barnette, who surged in popularity in the final days of the primary.
Toomey's Senate seat could prove to be one of the most competitive in the general election, as Democrats try to maintain control of a chamber split 50-50 by party.
Fetterman was projected to defeat his leading rivals, U.S. Rep. Conor Lamb and state Rep. Malcolm Kenyatta.
President Joe Biden in a congratulatory statement Tuesday night said Democrats are "united around John."
He "understands that working class families in Pennsylvania and across the country have been dealt out for far too long," Biden's statement said. "It's time to deal them back in, and electing John to the United States Senate would be a big step forward for Pennsylvania's working people."
The president also took a swipe at the Republican primary field.
"They have fought a malicious, chaotic primary campaign to be the most extreme," Biden said. "And they have shown people their authentic selves – that whoever emerges will be too dangerous, too craven, and too extreme to represent Pennsylvania in the United States Senate."
Fetterman's Senate bid took a turn over the weekend, when his campaign announced that the candidate suffered a stroke and was in the hospital. Fetterman said in a statement that he expects to fully recover, though the illness kept him off the trail in the final days of the primary.
Earlier Tuesday afternoon, the Democrat's campaign said that Fetterman had completed a successful surgery to implant a pacemaker with a defibrillator. He is resting at the hospital after the procedure, which lasted more than two-and-a-half hours, according to his campaign.