Ms. Brodie solid her vote early for Mr. Fetterman. “He doesn’t seem like a man who walked out of an Ivy League school,” she said. “He’s going to attach with different sorts of voters.”
At a recent debate, Mr. Lamb said he knew how swing voters felt about many issues. “They’re on the lookout for stability and caution of their leadership,” he said.
But that message, with its echoes of Mr. Biden’s 2020 campaign, could also be outdated.
Brendan McPhillips, who ran the Biden campaign in Pennsylvania, said Democratic voters are on the lookout for something different: candidates committed to fighting a Republican Party they view as lurching dangerously to the correct. While each Mr. Lamb and Mr. Fetterman support eliminating the Senate filibuster to pass Democratic priorities, Mr. Fetterman has gone further by making a frequent goal of Mr. Manchin, the Democrat who has blocked filibuster reform.
Mr. McPhillips said that caution was the mistaken message for the Democratic base today. “The stakes couldn’t be higher,” he said. “We’re running against literal fascists. We want to succeed in for bolder ideas.”
From the outset, Mr. Lamb’s fund-raising couldn’t compete with Mr. Fetterman’s appeal to a national cohort of small online donors. After launching its first TV ads in March, the Lamb campaign was forced to take them off the air for just about all of April, a vital month when voters were tuning in to the race. The campaign returned to TV late in April, and throughout the first week of May it spent $543,600 for ads in Philadelphia and Pittsburgh, based on AdImpact, an ad-tracking firm.
Mr. Fetterman’s TV ads have run constantly since March. He spent $537,000 in the primary week of May, reaching the state’s two major cities in addition to Wilkes-Barre and Harrisburg.
Some strategists said Mr. Lamb must have been aggressively attacking Mr. Fetterman in his ads — especially over a 2013 incident when Mr. Fetterman, who was the mayor of the town of Braddock on the time, brandished a shotgun to stop an unarmed Black jogger.