As the Bernie Sanders road show traveled south through Maine earlier this month, the crowds grew bigger and louder with each stop. About 650 people showed up at a convention center in Bangor, then 700 packed a former church in Lewiston, and finally more than 1,000 filled a high-school gymnasium in Biddeford. Sanders was stumping for Troy Jackson, the Democratic Senate candidate, and the faithful were nodding along to the hits. He pitched Medicare for All and raising taxes on billionaires. He decried wealth disparities (“an obscenity”) and Donald Trump (“the most dangerous president” in American history) with equal fervor.

What was surprising about Sanders’s appearance in the middle of one of the nation’s hardest-fought Senate races was less what he said and more that he was there at all. Mid-October in an election year is not usually Sanders’s busy season. The Vermont senator last had a tough race in his home state during President Bill Clinton’s first term. And although Sanders can draw a crowd like few other progressive politicians, Democratic candidates typically embrace him during primaries and then stick him on the sideline for the stretch run, when they’re rediscovering their love of capitalism and bipartisanship.

This fall, however, Sanders is in far more demand than usual. He’s campaigning for Democrats in some of the most competitive battlegrounds, entrusted not only with juicing turnout on college campuses—his assigned role in earlier years—but with persuading voters in Republican-leaning areas as well. From Maine, Sanders headed to Florida and then on to Texas and Michigan.

That Sanders finds himself, a decade after his first run for the presidency, arguably at the peak of his influence is all the more remarkable given that he recently turned 85 and that Democrats have spent the past two years wringing their hands over their party’s gerontocracy. According to YouGov, Sanders is the most popular current elected official in America—only the retirees Barack Obama and Arnold Schwarzenegger have higher ratings. Many of this year’s primary candidates whom Sanders backed defeated establishment opponents in states and districts that Trump had carried in 2024, and they now appear poised to help Democrats retake a majority in the House, and possibly the Senate.

And when the party’s 2028 presidential free-for-all kicks off, Sanders’s endorsement could be among the campaign’s most sought-after prizes.

“He will be seen as one of the most consequential political leaders of the 21st century,” Representative Ro Khanna of California, one of several Democrats who are likely to try to carry the Sanders mantle to the White House, told me. (Whether offering such high praise will help win Sanders’s nod is another question.) Khanna noted that Sanders’s appeal may be on the upswing precisely because he’s not running for office, and unless he intends to stay in the Senate into his mid-90s, he is unlikely to do so again.

But in interviews over the past few weeks, candidates, strategists, and voters across the political spectrum attributed Sanders’s sudden October relevance to the mainstreaming of ideas that he has championed for years. Attacks on big corporations are now a hallmark of both parties. As many as two-thirds of American voters support Sanders’s signature Medicare for All proposal, long derided by Republicans as socialized medicine, according to a recent poll. Democrats who were stung by a second loss to Trump are rethinking their assumptions about what the public really wants.

“Anyone who wants to win an election right now is a populist,” Phil Gardner, an adviser to centrist Democrats, told me. About Sanders, he said: “There is an increasing realization that his ideas have more currency and popularity than people might have thought back in 2016.”Sanders has shown few obvious signs of slowing down, either politically or physically. At each of his rallies in Maine, teleprompters that were in place for Jackson’s speech came down when it was Sanders’s turn to speak.

His aides say that he checks in frequently with questions about logistics or policy. (Two of my own conversations with them were interrupted because Sanders was calling on the other line.) Sanders was also quicker than much younger politicians to recognize the public’s growing fears about AI, and he’s been one of the most aggressive leaders on the left in demanding more regulation of the industry and a moratorium on new data centers. Democrats are begging not only for his presence in key states and districts, but for his financial help as well: He’s raised millions of dollars for candidates during this election, and last week he gave $1 million to boost Abdul El-Sayed’s U.S. Senate candidacy in Michigan.

Unlike most politicians, Sanders avoids talking much about himself. During his Maine speeches, he made only glancing references to his growing influence. At one point, he noted that he’s been talking about oligarchy for a number of years. “Before I started talking about it, people would say, What the hell is an oligarch?” he told the crowd in Bangor. Then he added, to a loud cheer: “People know what oligarchy is today.”

I met Sanders after the speech, and when I asked him to explain his widening appeal, he initially shrugged as if to dismiss the question. But he could not completely hide his satisfaction with the sense that after he spent decades on the fringes of political debates, the country was moving in his direction. “I think the American people are undergoing a massive transformation in their views,” Sanders told me. “So maybe Bernie Sanders has not been all that crazy over the years.”

Sanders has always had a complicated relationship with the Democratic Party. He sought its presidential nomination twice, but he still likes to remind voters that he has run for election to the Senate as an independent. (Along with the Senate’s other independent, Maine’s Angus King, he caucuses with the Democrats.) Despite that distinction, he began his remarks in Maine by urging voters to set aside every consideration but party label when they cast their ballot. “If you want to hold Donald Trump and his disastrous policies accountable,” Sanders said, “the only way we do that is by electing a Democratic Senate.”

The pitch was clearly aimed at the many independents and Democrats who have supported Senator Susan Collins, a moderate Republican, in previous years.

At the same time, Sanders also heaped plenty of criticism on Democrats, accusing them of kowtowing to corporate donors and ignoring the needs of the working class. “The Democratic Party itself is significantly responsible for the rise of Trumpism,” Sanders told me. He made clear that he hoped that the election of a slate of progressive Senate candidates—which includes Jackson, El-Sayed, Peggy Flanagan in Minnesota, and Angie Nixon in Florida—would force the party to pursue policies it has previously deemed too radical.

All four of these candidates have also called for replacing Chuck Schumer as the Democrats’ Senate leader. Sanders is not going that far yet, but he told me that he would support a leader “who’s going to fight for Medicare for All”—a position that Schumer has yet to embrace. Sanders, too, could have more say in shaping party policy: He’s in line to become chair of the Senate’s powerful Committee on Health, Education, Labor, and Pensions if Democrats win the majority.

One reason Sanders is so much busier this fall is that so many of the candidates running in big races have him at least partially to thank for their nomination.

Sanders endorsed more than 80 candidates for federal, state, and local offices this year—a higher total, his aides told me, than he has backed in the past. By their count, nearly 75 percent of them won their primary. He had a few misfires; most notably, Sanders was an early endorser of Graham Platner’s Senate candidacy in Maine and stood by him through a series of controversies. Sanders joined Democrats in abandoning Platner after he was accused of sexual assault, an accusation which he denied. (“Let’s not get into Platner,” Sanders told me when I brought him up.)

Plenty of candidates have sought Sanders’s endorsement without getting it. Sometimes a simple Google search reveals that a candidate is not as progressive as they claim to be. Desperation is another turnoff. “The candidates that we don’t support,” he said, “are, Oh, Bernie, support me. You’re going to be my savior. I’m not doing anything [to win], but I need your name on my literature. That we don’t support.”

In some cases, a nonendorsement from Sanders can be as consequential as his blessing. During Wisconsin’s primary for governor, neither Sanders nor Representative Alexandria Ocasio-Cortez chose to endorse Francesca Hong, a democratic socialist who surged into a polling lead while running on a platform closely aligned with Sanders. She also had the support of Sanders allies such as Khanna and Our Revolution, a group that sprang out of his 2016 campaign but is no longer affiliated with the senator.

Hong ended up losing the primary to the establishment-backed David Crowley by fewer than 4,000 votes statewide, a result so close that a Sanders endorsement might have made the difference.

Democratic leaders, worried that Hong’s nomination would have cost the party during the general election, cheered Crowley’s narrow victory. Sanders told me he had no regrets. His focus this year, he said, has largely been on federal campaigns. “I don’t know anything about the problems facing Wisconsin,” Sanders said. (That may be true, but some of his other endorsements include people running for county supervisor in Iowa; the city council in Tempe, Arizona; and mayor of Fontana, California.)

The candidates Sanders has endorsed in U.S. House races reflect his new position closer to the center of the Democratic coalition. Several such candidates have also earned the backing of the Blue Dogs, a group that has long prioritized fiscal discipline and, in the past, likely would have steered clear of an alliance with the free-spending Sanders. What these “Bernie Dogs” have in common are a working-class background—the group includes a firefighter in Pennsylvania and an ironworker in Ohio—and a populist message.

Sam Forstag, a smoke jumper running to flip a Republican-held seat in Montana, told me that if he wins, he would join both the Blue Dog Coalition and the Congressional Progressive Caucus. Forstag had been working with a group defending Forest Service workers from Trump-administration cuts last year when Sanders added a stop to his “Fighting Oligarchy” tour in Missoula and asked whether Forstag, a union leader and federal employee, would speak.

The rally drew a crowd of 9,000 people on a Wednesday afternoon, and soon after, Forstag decided to run for office. Forstag had nothing but praise for the man who kick-started his political career. Sanders, he told me, “is one of a very small group of people in the U.S. Senate, let alone the House, who people can tell are just speaking truth. Even if you don’t agree with everything, he is not somebody who’s bound down to a party boss, and that is far too rare in today’s politics.”

At least on the House side, Sanders is not demanding ideological purity. Democrats such as Brian Poindexter, who is challenging Representative Max Miller, a Republican in a Trump-carried district outside Cleveland, and Rebecca Cooke, a candidate in western Wisconsin, are not running on Medicare for All. Sanders told me he’s okay with that. “There’s no litmus test,” he said. When I asked him whether he worried about diluting his brand, he sounded for a moment more like a conventional party leader than an anti-establishment insurgent.

Citing Cooke as an example, Sanders said: “She comes from a fairly conservative district. She knows her district very, very well, and I trust her judgement.”He added: “If she was running in New York City, maybe it would be different.”Sanders is not the only progressive favorite campaigning in tough swing-state races this fall. Ocasio-Cortez has also stumped alongside Jackson and El-Sayed, and Jackson invited Senator Elizabeth Warren up to Maine after Sanders’s visit.

Meanwhile, some Democrats still aren’t rushing to appear with Sanders in the home stretch. Forstag told me that he’d be campaigning with fellow Montanans, not Sanders, as his race draws to a close. In Texas, James Talarico, the party’s standard-bearer for Senate, did not attend Sanders’s events, and neither did the Democratic candidate for governor, Gina Hinojosa.

Whether the visits by Sanders and his progressive allies will help or hurt Democrats in the Senate battlegrounds should become clear next week. In Maine, Collins sensed an opportunity to seize the political center: As Jackson hosted Sanders and then Ocasio-Cortez, she campaigned with the former Democratic Senator Joe Manchin of West Virginia. “Troy certainly has every right to invite whomever he wants to campaign with him in Maine,” Collins told reporters as she stood alongside Manchin.

“So far it’s been from the far left of the party.”Jackson was betting that even near the end of Sanders’s career, he could still bring out new voters. At the rally in Lewiston, I met Robert LaGrange, a retired cook who had come to see Sanders and told me that he would be voting this year for the first time in his life. “I just didn’t think my vote counted,” he said. Others told me that they were pleasantly surprised to see Sanders during the general election.

“People are more willing to listen to him now with all that’s going on,” Mary Gilman, a retired teacher from Belfast, told me. Devyn Campbell, a 26-year-old fisherman from Boothbay, said he was glad to see Democrats such as Jackson campaigning with Sanders instead of “aggressively centrist” surrogates. “It shows the Democratic Party has finally learned its lesson after the last election,” Campbell told me.

Sanders has also spent time in the past two years working with Run for Something, a group formed during Trump’s first term that is devoted to recruiting first-time candidates. Its president, Amanda Litman, has been among the loudest Democratic voices calling for the party’s older leaders to step aside; she has said that anyone over the age of 75 should not run for another term. But she sees no contradiction in Sanders’s enduring popularity in the middle of his ninth decade. “Should Senator Sanders run for reelection again? Absolutely not,” Litman told me.

“That doesn’t mean he isn’t up to the moment, but part of the way I think he is proving himself up to the moment is succession planning.”I asked Litman whether she saw Sanders as passing the torch or holding onto it. She dodged: “He is using the institutional power he has to prepare to pass it,” she replied.

Sanders is now getting a warmer welcome from a party that had long held him at arm’s length—and that he has long refused to fully embrace. This renewed appreciation may have come too late for Sanders’s presidential ambitions, but the Democratic message in the twilight of the Trump era sounds more and more like his own.