Pennsylvania Senate election: Republican Dave McCormick wins seat

The Republican Dave McCormick won the Senate race in the battleground state of Pennsylvania on Thursday, denying the Democratic incumbent, Bob Casey, a fourth term and expanding his party's majority in the upper chamber.

When the Associated Press called the race at 4.09pm ET on Thursday, two days after polls closed in Pennsylvania , McCormick led by 0.4 points. The narrow margin raised the possibility of a recount, although his victory is expected to stand given his lead of roughly 30,000 votes.

With McCormick's victory, Republicans have now secured at least 53 seats in the Senate, erasing Democrats' previous majority in the chamber. Two Senate races in Nevada and Arizona remained too close to call as of Thursday afternoon.

Although he fell short, Casey outperformed Kamala Harris, who lost Pennsylvania to Donald Trump by two points. Trump also won the two other "blue wall" states of Michigan and Wisconsin, but Democrats managed to hold on to both Senate seats that were up for grabs in those states.

The call in Pennsylvania brought an end to a contentious and expensive Senate race that saw the two candidates trade barbed attacks on the cost of living, abortion access and McCormick's recent residency in Connecticut. Casey attacked McCormick, a former hedge fund CEO, as out of touch while McCormick linked Casey to the "reckless" government spending of the Biden administration.

At their debate last month, Casey mocked McCormick as "bought and paid for by these billionaires and corporations". McCormick returned fire, saying: "When you don't have a record to run on, which Senator Casey does not, you attack your opponent."

The high stakes of the race made it into one of the most expensive Senate elections in the nation, as the dueling campaigns and their allies spent more than $300m on ads. One pro-McCormick organization, the Keystone Renewal Pac, spent at least $54m on the race, making the group the highest-spending single-candidate Pac involved in a Senate race of this election cycle.

Most public polls of the race showed Casey leading by several points up until recent weeks, when McCormick narrowed that gap to just a few points. Despite that trend, Casey appeared to be in a slightly stronger position than Harris , who was running neck and neck against Trump in Pennsylvania up until election day. Leaders of both parties had identified Pennsylvania and its 19 electoral votes as the potential tipping point in the presidential race.

"I think both races are going to be very close, but I think the people of our state know it's a very, very clear choice," Casey told the Guardian in September. "It's never been clearer."

Before election day, Democrats held a 51-49 majority in the Senate. Republicans ' victories in Montana, Ohio and West Virginia had already guaranteed control of the Senate, but McCormick's win will give the party even more leverage to enact Trump's agenda when the new Congress is seated in January.

Read more of the Guardian's 2024 US election coverage