Trump, messaging, and money: How Dave McCormick unseated Bob Casey in Pennsylvania’s Senate race

Aside from once-and-future President Donald Trump’s unexpectedly decisive win, one of the most surprising results in Tuesday’s election was Republican Dave McCormick’s apparent victory over three-term U.S. Sen. Bob Casey Jr. (D., Pa.).

Casey has not conceded the race, and it’s possible that the narrow-margin lead will trigger Pennsylvania’s automatic recount process once more ballots are counted. But the Associated Press called the race for McCormick on Thursday, and Casey faces major obstacles in reversing the result.

» READ MORE: In a stunning upset, Republican Dave McCormick unseats longtime U.S. Sen. Bob Casey, according to the AP

Assuming the AP’s call stands, the result will be an earthquake in Pennsylvania politics. Casey, a moderate who often outperforms leading candidates in his party, had won six statewide elections in Pennsylvania, and his father was a well-known governor.

Christopher Nicholas, a veteran Pennsylvania Republican strategist, said that Casey’s popularity had been falling for months and that McCormick, a former hedge fund executive with ample money behind him, was well-positioned to take advantage.

“You always look at the incumbent’s poll numbers and the challenger’s money,” said Nicholas, who worked on the late Sen. Arlen Specter’s campaigns. “Casey’s numbers kept on floating down. He was a typical lead-from-behind type of fellow. And once his poll numbers fell below 50, it’s always hard for an incumbent to move back up.”

Casey’s three wins in Senate races all came during strong Democratic years: the 2006 midterm election, which was dominated by the growing unpopularity of the Iraq War and then-President George W. Bush; former President Barack Obama’s 2012 reelection; and the 2018 “Trump pushback cycle,” as Nicholas put it.

“Casey, unlike in his other three Senate runs, didn’t have the wind in his back,” Nicholas said. “He’s never had to worry about a tough October.”

So how did McCormick pull off the win? It came down to Trump, messaging, and money.

In 2012, Casey outperformed then-President Barack Obama by 1.7 percentage points among Pennsylvania voters, and his margin of victory over GOP Senate candidate Tom Smith was 3.7 percentage points greater than Obama’s over Republican Mitt Romney.

This year, observers expected Casey to once again best his party’s ticket, potentially allowing him to survive even if Vice President Kamala Harris lost narrowly to Trump in the Keystone State.

That formula failed to save Casey for two reasons. First, he didn’t outperform Harris. Casey is on pace to take 48.5% of the vote, the same share that Harris appears to have won in Pennsylvania. He may even end up with slightly fewer votes than her once the counting is finished, which would be a shocking outcome given Casey’s history.

» READ MORE: Donald Trump won Pa. with more votes than any statewide Republican candidate in history. Here’s how he did it.

The incumbent’s other problem was that Trump did better in Pennsylvania than expected. In Wisconsin and Michigan, the other two “blue wall” states, Trump won by less than 1 percentage point and Democrats held onto Senate seats. In Pennsylvania, Trump appears to have won by about 2 percentage points.

But there was still hope for Casey because McCormick, who had 48.9% of the vote as of Friday afternoon, underperformed compared with Trump, who had 50.5%. So despite not winning more votes than Harris, Casey appears to have outperformed her by 1.5 percentage points in terms of his margin, due primarily to having a less popular opponent, and he still could have eked out a victory.

If Casey had outperformed Harris to any meaningful extent, he would have won reelection.

Casey had better margins than Harris in several postindustrial areas like Lackawanna County, which includes Casey’s hometown of Scranton.

But his margins fell behind the vice president’s in three counties that give Democratic candidates their biggest advantages in Pennsylvania: Philadelphia, Montgomery, and Allegheny, which includes Pittsburgh.

In Philly, for instance, Casey has taken 78% of ballots counted so far, while Harris has 79%. That 1-percentage-point difference amounts to more than 26,000 votes — although part of that gap is due to more people voting in the presidential election.

Meanwhile, Bucks County, continuing to earn its reputation as one of the most purple counties in Pennsylvania, appears to have backed Trump and Casey. Bucks still has thousands of provisional, military, and overseas ballots left to tally. But if Trump’s lead holds, he would be the first GOP presidential candidate to carry the county since 1988.

Overall, Casey is poised to win 12 of Pennsylvania’s 67 counties. But his share of the vote decreased in every county compared with his most recent reelection campaign in 2018, a strong year for Democrats.

His support decreased most dramatically in Greene and Fayette Counties, deep in Trump country on the West Virginia border.

One reason Casey might not have outrun Harris is that McCormick worked relentlessly to tie Casey to the vice president.

The Republican and his allies blanketed the airwaves with ads calling Casey a “weak career politician” who would be a “rubber stamp” for Harris’ agenda, noting that he voted with her and President Joe Biden’s administration nearly all of the time.

Casey, meanwhile, tried to play defense with ads touting his alignment with Trump’s protectionist trade policies.

(Conversely, Casey’s aggressive attack ads on McCormick — questioning his ties to Pennsylvania and highlighting investments McCormick’s old hedge fund made in China — might have been the reason the Republican couldn’t keep up with Trump.)

» READ MORE: Why Sen. Bob Casey has changed his positions on abortion and same-sex marriage — and why his opponent doesn’t talk much about it

Another reason Casey didn’t best the Democratic ticket may be that the incumbent’s politics are now more aligned with his party’s orthodoxy than they were when he began his Senate career as a “pro-life Democrat” who opposed new gun regulations and same-sex marriage. Although he still stands to the right of his party on energy issues, he now supports marriage equality, a national guarantee of abortion rights, and new gun-control measures.

Although McCormick had Trump’s coattails and an apparently successful messaging strategy, none of that would be enough without money. And thanks to a Wall Street-backed super PAC, McCormick had a ton of it.

» READ MORE: Meet the billionaires backing Republican Dave McCormick’s U.S. Senate run

Keystone Renewal PAC was the only outside spending group that was dedicated solely to Pennsylvania’s Senate race. A vast majority of the rest of the money spent in the race came from the candidates’ campaigns and their parties.

Challengers to longtime incumbents often struggle to raise money. But McCormick is a former CEO of Bridgewater Associates, the largest hedge fund in the world, and he has connections with some of the world’s richest people.

Many of the donors to Keystone Renewal know McCormick personally, and the PAC’s spending helped make him financially competitive in the more than $300 million race.

The PAC spent about $54 million, according to the government transparency organization Open Secrets. About $41 million of that was spent attacking Casey, while $13 million went to boosting McCormick.

Keystone Renewal’s largest donor was Ken C. Griffin, the billionaire owner of Citadel Securities, a financial services company. It also received millions from Jeff Yass, the richest man in Pennsylvania and an ardent supporter of “school choice” policies, which McCormick favors.

Staff writer Katie Bernard and graphics editor John Duchneskie contributed to this article.