Public polling in Pennsylvania has been sparse and there is theoretically still time for the Democratic race to be upended. But so far, there has been little evidence that any issues about his past or his persona have dented enthusiasm for Mr. Fetterman among many Democratic primary voters.
He ran unsuccessfully for Senate in 2016 but built a devoted following, and after defeating an incumbent to win his party’s nomination for lieutenant governor, he has been a visible statewide presence in office. He had attracted national attention as mayor of Braddock, a struggling former steel town he worked to help revitalize. But he drew new levels of notice as a cable-television fixture when Pennsylvania’s 2020 votes were being counted.
His campaign has had an overwhelming fund-raising advantage, a head-start on television advertising and an early entry into the race. Representative Conor Lamb — the polished moderate from Western Pennsylvania who has emerged as his closest rival — entered the race later and amassed notable institutional support, but has struggled to break through statewide or to effectively define Mr. Fetterman in negative terms.
On Thursday night, as he made the rounds at The Holy Hound, attendees clamored for selfies and offered him French fries or a beer — Mr. Fetterman, who often holds campaign events in breweries and bars, ruefully declined. “Hell yeah!” he replied to a young attendee who requested a photo. He thanked another supporter who had already voted for being “triple awesome.”
“I feel like I could get a beer with Fetterman and we’d hit it off,” said Robert Keebler, 45, a union worker in suburban Pittsburgh.
Mr. Fetterman is widely considered a progressive candidate who promotes issues like raising the minimum wage, legalizing marijuana and eliminating the filibuster, and fighting for voting rights, abortion rights and protections for L.G.B.T.Q. people.
“Some folks, you know, will be like, ‘The Democrats! The culture wars! What are you going to do?’ I’m like, ‘Bring it on!’” Mr. Fetterman said in York. “If you get your jollies or you get your voters excited by bullying gay and trans kids, you know, it’s time for a new line of work.”