Bernie Sanders is not running for president. But he is drawing larger crowds now than he did when he was campaigning for the White House.

The message has hardly changed. Nor has the messenger, with his shock of white hair and booming delivery. What’s different now, the senator says, is that his fears – a government captured by billionaires who exploit working people – have become an undeniable reality and people are angry.

“For years, I’ve talked about the concept of oligarchy as an abstraction,” Sanders, an independent who votes with Democrats and twice sought the party’s presidential nomination, said in an interview after a joint rally in Tempe, Arizona, with the New York representative Alexandria Ocasio-Cortez. The Vermont senator recalled Donald Trump’s inauguration, when the three wealthiest people on the planet – Elon Musk, Jeff Bezos and Mark Zuckerberg – were seated in front of his cabinet nominees in what many viewed as a shocking display of power and influence.

“You gotta be kind of blind not to understand that you have a government of the billionaire class, for the billionaire class, by the billionaire class,” he said. “And then, on top of all that, you’ve got Trump moving very rapidly toward an authoritarian form of society.”

Two months after Trump was sworn in for a second term, Democratic activists and an increasingly vocal chorus of voters say they are terrified, angry and desperate for leadership. In something of a third act, the 83-year-old democratic socialist is stepping in to fill the void.

But his aim is not only to revive the anti-Trump resistance movement – he wants a bottom-up overhaul of the American political system.

“It’s not just oligarchy that we are going to fight. It’s not just authoritarianism that we’re going to fight,” Sanders told an arena full of supporters at Arizona State University on Thursday night. “We will not accept a society today in which we have massive income and wealth inequality, where the very rich have never done better while working families are struggling to put food on the table.”

For weeks, voters have been showing up at town halls to vent their alarm and rage over the president’s aggressive power grabs and the Musk-led mass firings of federal workers. But they are also furious at the Democratic leadership, charging that the party that spent an entire election season warning of the threat Trump posed to American democracy, and yet now appeared either unable or unwilling to stand up to him.

At the rally in Tempe, several attendees demanded more defiance.

“Them just holding paddle boards up and staying quiet or wearing pink blazers is not enough,” said Alexandra Rodriguez, 20, of Mesa, referring to the Democrats’ acts of protest during Trump’s address to Congress earlier this month. “I think they do need to be willing to go to extremes.”

Several attendees expressed outrage at the Senate minority leader, Chuck Schumer, who, faced with what he called a “Hobson’s choice” between supporting a Republican-authored funding bill or inciting a government shutdown, wrangled a coalition of Democrats to pass the spending measure. The decision has unleashed a torrent of anger from his party’s base, forcing him to postpone a book tour as he defends himself against calls to step down as leader. On Sanders and Ocasio-Cortez’s western tour, the New York representative was interrupted by intermittent calls to “Primary Chuck!”

“This isn’t just about Republicans, either. We need a Democratic party that fights harder for us, too,” Ocasio-Cortez said in Arizona, drawing some of the loudest, most sustained applause of the event. She urged attendees to help elect candidates “with the courage to brawl for the working class”.

Democrats “absolutely need to get stronger”, Audree Castro, 52, said as she waited with her mother and aunt to enter the venue on Thursday night. “I want my democracy back.”

In recent weeks, Democrats have sought to capitalize on the bubbling backlash to the disorienting opening months of Trump’s second term. Following Sanders’ lead, many Democrats are hosting town halls in Republican-held districts to draw attention to Musk’s slash-and-burn cost-cutting project and Republican proposals that would almost certainly result in cuts to social safety net programs.

Robbie Lambert, 70, a retired special education teacher, said keeping up with the turmoil in Washington was beginning to feel like a full-time job. Just that afternoon, Trump had signed an executive order aimed at dismantling the Department of Education.

“You feel helpless. It’s like, what can we do?” said Lambert, who was on vacation in Arizona and decided she had to attend the Tempe rally. “Coming together, talking with people here, makes you feel like you’re doing something.”

The Arizona representative Yassamin Ansari, who attended Thursday’s rally, said she had been hearing similar calls for action from constituents across her district this week, including at an event with LGBTQ+ business leaders and an at-capacity town hall, where several people shared that it was the first political event they had ever attended.

“People are really fed up,” Ansari said in an interview.

For now, at least, Sanders and Ocasio-Cortez are the most prominent Democrats offering both a strategy to confront Trump and an alternative vision for the party.

In 2024, Democrats lost support among young people and Latino voters – core constituencies – and recent polling found that the party’s popularity is at an all-time low. Few Democrats disagree that their party needs to course-correct, but how and to what degree remains a topic of intense debate.

Supporters say the success of Sanders’ tour, which began last month in Omaha, Nebraska, is a clear sign that Democrats want the party to aggressivelyfight what they view as Trump’s encroaching authoritarianism – not “roll over and play dead”, as veteran strategist James Carville suggested in an op-ed. They also view it as an endorsement of Sanders’ policy agenda, arguing that his brand of economic populism is the right match for this political moment.

According to a memo by Sanders’ longtime adviser, Faiz Shakir, the senator has raised more than $7m from more than 200,000 donors since February, and is drawing crowds 25% to 100% larger than at the height of his presidential campaigns in 2016 and 2020. On Friday, more than 30,000 people attended a rally in Denver – the largest audience Sanders has ever drawn, his team said.

“We’re living in an intensely populist moment right now,” Shakir wrote. “It’s not ‘left versus right’. It’s ‘very top versus everyone else’.” The title of his memo: “It’s a populist revolt, stupid.”

The joint appearance by the 35-year-old New York representative and the Vermont senator who she has said inspired her to run for office naturally raised the question: is Ocasio-Cortez the heir to the progressive movement Sanders has been building since before she was born? Several rally-goers in Tempe believed she had the potential to lead the party – and perhaps even the country.

“When AOC has something to say, I listen,” said Jonas Prado, 32, a first responder.

“I hope she’s the first woman president,” said Norman Ellison, 60, a mechanical engineer.

There was also a tinge of wistfulness in the arena. Supporters dressed in old campaign t-shirts and hats and one person sported a pin that said, “Bernie was right.”

Sanders, who has all but ruled out a third run for president, was in vintage form, delivering a blistering, 50-minute critique of the “top 1%” with the moral ferocity that has long endeared him to legions of politically disaffected supporters.

The senator named names, accusing executives from the fossil fuel, insurance and pharmaceutical industries of being “major criminals”, while sharing stark statistics on wealth inequality in the US that elicited boos and gasps from the audience. At one point, Sanders cited an analysis released by his Senate committee that found the wealthiest Americans live an average of seven years longer than poorer Americans.

“In other words, being working class in America is a death sentence,” he bellowed.

Ocasio-Cortez’s opening remarks were no less visceral. She charged that Trump and Musk, his billionaire lieutenant, were “taking a wrecking ball to our country” and “screwing over” working people. “We’re gonna throw these bums out,” she declared.

While both Sanders and Ocasio-Cortez share a political vision, their double act showcased the distinct styles of two progressive leaders at opposite ends of their career arcs.

Ocasio-Cortez offered a more personal touch, weaving elements of her biography into her speech – something Sanders is typically loath to do. She spoke of her mother, who cleaned homes, and her father, whose death from a rare form of cancer plunged the family into economic uncertainty.

“I don’t believe in healthcare, labor and human dignity because I’m an extremist,” she said, pushing back on the rightwing caricature of her. “I believe in these things because I was a waitress.”

She said she empathized with Americans who felt overwhelmed and demoralized, and encouraged them not to give in to despair. “We won’t do that,” someone in the crowd yelled.

When the event concluded, Sanders and Ocasio-Cortez left the arena to address an overflow crowd that hadn’t been able to get in.

“This is where the future is,” said Sebastian Santamaria, 25, gesturing toward the empty podium adorned with a “Fight Oligarchy” placard. “As a person who has supported Democrats in the past, I don’t want to keep supporting you if it doesn’t look more like this.”