PITTSBURGH—So far, the 2020 election is playing out exactly as Bernie Sanders had hoped. And that has Sanders thinking with growing seriousness that this could very well end with his election as president.

Still, since some political observers and journalists haven’t wrapped their head around the reality that he could be more than a spoiler who kneecaps the party en route to a complicated convention and maybe another loss to Donald Trump, Sanders has been able to do this without the attention or scrutiny that anyone else with his poll numbers, fundraising, and crowds would face.

The campaign is moving toward its internal $280 million target and savoring polls that have Sanders just behind Joe Biden, who Sanders and his team expect will only go down once he gets in the race. The number of candidates keeps growing, lowering how many people it would take to come in first, beyond the 15 to 20 percent of primary voters who will stick with Sanders no matter what.

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Aides say that Sanders is envisioning himself in the Oval Office, which has been guiding his decisions on both campaign operations and policy positions. Their assessment is that Americans want Medicare for all, but are just anxious that Sanders wouldn’t be able to manage that or any of the other big changes he’s promising. They believe that a tightly run campaign would demonstrate that he could run the country, too. (That’s a huge shift from his last run, which, even as it caught fire in the primaries, never reached a level beyond joking about making his 2016 campaign manager, Jeff Weaver, the ambassador to the Vatican). They’re also hoping that the intensity of the campaign counters the three main weaknesses they’ve identified: that Sanders is too old, that people are scared off by the prospect of “socialism,” and that they hold not being a Democrat against him.

“There’s a three-out-of-four chance we are not the nominee,” Faiz Shakir, Sanders’s current campaign manager, says he tells the senator, “but that one-in-four chance is better than anyone else in the field.”

The senator from Vermont’s pitch is a mix of idealism and a shouting anger about the system, but at its heart is a hard-nosed math: He’s the only candidate with a sizable chunk of the electorate that won’t waver, no matter what, so a field that keeps growing and splitting support keeps making things easier.

He’s counting on winning Iowa and New Hampshire, where he was already surprisingly strong in 2016, and hoping that Cory Booker and Kamala Harris will split the black electorate in South Carolina and give him a path to slip through there, too. And then, Sanders aides believe, he’ll easily win enough delegates to put him into contention at the convention. They say they don’t need him to get more than 30 percent to make that happen.

So he’s eagerly gotten into fights, like one over the weekend with the Center for American Progress about a video produced by an affiliated website that speciously accused him of profiting off his 2016 run. And then he’s fundraised by citing the fights as evidence of resistance to the revolution he’s promising.

It is all wrapped in a tale Sanders tells of Democratic politics in which he is already the central figure—“only one name, and one name only,” as San Juan Mayor Carmen Yulín Cruz, a campaign co-chair, introduces him at rallies. Some of that is apparent: Medicare for all has become a litmus test for many progressives, as has free public-college tuition. Some of the tale, though, comes closer to solipsistic embellishment, like when Sanders says in his stump speech that “a funny thing happened over the last four years” and ticks through Democrats supporting investment in infrastructure, prioritizing climate change, and reforming the criminal-justice system—all of which were top focuses for Barack Obama.

Walking around a Sanders rally here on Sunday at Schenley Plaza, across the street from the University of Pittsburgh’s campus, it was hard to find a person who was not exactly the kind of voter the senator from Vermont believes will win him the nomination and make him the most electable in the general election: absolutely committed to him; very skeptical that there’s any other Democratic candidate to consider, or one who would be worth supporting in a race against Trump.

There was Tyler Litzinger, a Starbucks employee who came here on Sunday with three friends, who said that he is in the same place now as he was in 2016, when he supported Sanders but refused to vote in the general election after the senator lost in the primaries. Would he vote in the election if the 2020 nominee is anyone other than Sanders? “No,” he said. “I was one of those.” And as the one friend who said he’s still undecided between Sanders and Elizabeth Warren ribbed Litzinger and said, “We’re working on that,” the 25-year-old stood his ground. He doesn’t know if Sanders can get anything that he’s talking about done, Litzinger said, but Sanders winning is the only thing he’s interested in. As for the idea that that might help reelect Trump, he said, “I don’t follow that.”

Kelly Brown, a former reporter who left her job for what she said were the more reliable wages of being a post-office clerk, waved away her husband, who was trying to intercede, when I asked her if she’d support anyone else. “You have to think long and hard,” she said. She’d still vote next November, Brown insisted, but it would be a tough sell to vote for a non-Sanders Democrat. “We’re told the lesser of two evils,” she said, “but at some point you have to recognize it’s still evil.”

Michelle Renzo, a 46-year-old nursing assistant who said she was turned onto Sanders in 2016 by her then-13-year old son, who came with her to the rally, made a frightened expression when I asked her what she’d do if Sanders doesn’t get the nomination.

“I haven’t thought that far into it,” Renzo said.

Talking to people in a crowd of thousands—the Sanders campaign tracks each event in a spreadsheet, and says the count there was 4,500— isn’t as scientific as a poll, but of the people that I talked to on their way into the rally more than two hours before it began, only one committed Sanders voter told me that he’d be ready to support another nominee: Bill Wekselman, a 67-year-old retired lawyer and law clerk, who said, “Bernie’s my guy.” But as for not showing up against Trump, “I can’t imagine doing that,” he said.

“I think we have proven we have a dedicated group of supporters that make up a significant number of voters in a Democratic primary,” said Ari Rabin-Havt, the campaign’s chief of staff, looking out at the crowd shortly before Sanders started speaking on Sunday afternoon. “It puts us in a place that we can very much grow.”

The most concentrated ambivalence about Sanders came from a handful of people in red T-shirts from the Democratic Socialists of America (DSA) who’d set up a table near the security check at the entrance. Does the Democratic-socialist senator seem like the best choice? “To an extent, yeah,” said one, who didn’t want to give his name, and who said that the group had issued talking points that they weren’t supposed to stray from. (Another DSA member who spoke with me about supporting Sanders but not others later found me in the crowd and asked not to be identified by name, citing the internal politics of the group and a fear of being targeted.)

Sanders himself has said he’ll do whatever needs to be done to defeat Trump—Rabin-Havt said the reelection of Trump would be a “cataclysmic event”—but the senator also knows that many of his supporters won’t vote for any other Democrat, just like they wouldn’t in 2016, despite all the campaigning he did for Hillary Clinton.

Doubters suspect a Sanders nomination could be the one sure way to give Trump a second term, but Sanders’s thinking is that he could get the same Democratic and anti-Trump votes as other nominees, plus all the people who would only vote for him. Over at the campaign’s Washington, D.C., headquarters, they love the video from Sanders’s October 2017 CNN debate with Ted Cruz, when he convinced an antagonistic questioner that higher taxes to match those of European countries make sense. After Monday night’s town hall on Fox News, they have even more moments like that, including when Sanders surprised the anchors by getting the crowd to whoop for government-run health care.

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That’s the case Sanders and his aides have been making as they’ve undertaken an outreach effort unlike anything from the last campaign, spending hours on phone calls trying to talk political leaders down from being completely opposed to him. They have a basic script: Start out asking where the support for Sanders is among their constituents, then ask why they think those people support him, and then ask the leaders to explain their own skepticism.

There’s evidence that the effort is working. Two weeks ago, at the National Action Network conference in New York, the Reverend Al Sharpton recounted a lunch in Harlem that he’d had with Sanders late into the 2016 primaries, full of promises for more attention and outreach.

“I want you to know that he has done what he said,” Sharpton told the crowd. “The term’s not over; this is not the finals. But so far, you get a passing grade.”

So, Sharpton said, he was ready to take Sanders seriously. “Before when he said it, it sounds like a dream. Now people are saying, ‘Wait a minute, we’ll see,’” Sharpton said, welcoming him onstage.

The audience, made up of black activists who were largely seen as the kind of voters most opposed to Sanders in the last campaign, cheered as he walked up, and stayed with him even as he delivered, screaming into the microphone, the same stump speech he gives at nearly every stop.

Sanders and his aides believe that he’s already dispatched whatever questions over his record and background will come, given what was litigated in his 2016 race. He’s taken open questions from reporters a total of once so far in his two months on the trail, while other candidates take them constantly. He’s mostly dropped talking about his life story, despite all the fanfare his campaign stoked at his launch by saying that it was going to be a new theme of this run. He drove Democratic insiders crazy by agreeing to the Fox News town hall a few weeks ago, providing cover just at the moment when the channel was facing a growing boycott over controversial comments by the host Tucker Carlson.

Yes, there was a band of young white guys in hockey jerseys playing a song about “cosmic dust” ahead of the Pittsburgh rally, and staffing tables of merchandise with Sanders as a Sesame Street character, and Let it FUCKING Bern written over a picture of a marijuana leaf. But there was also an operation that included a bus for traveling press, and orange webbing over bicycle gates to keep the press from interacting with the crowds once they arrived, and staff to track attendees on iPads and hand out blue-and-white campaign signs to wave while he spoke.

John Fetterman, the Pennsylvania lieutenant governor, who supported Sanders in 2016 and was endorsed by Sanders in his own race last year, is staying neutral for now, and wasn’t at the Pittsburgh rally.

But he said he doesn’t believe that the “Bernie or bust” movement will survive if the nomination doesn’t go Sanders’s way.

“Any Democrat that is not going to get behind and rally whoever the nominee is, I just don’t know what world they’re living in,” Fetterman said. “They might be fired up; they might be in the heat of the moment. But that’s my base. I don’t believe that my base would not go for round two if Bernie’s not the nominee.”