Sanders, the 78-year-old presidential candidate, gripped the microphone and leaned over his lectern to somberly recount the last month of his medical history: the blocked artery, the hospital stay, two stents. But his voice rose as he bragged about the pace of his campaign now — four events that day, plus a long walk.

CEDAR RAPIDS, Iowa — Senator Bernie Sanders was holding court on the topic of health care for senior citizens last weekend when a bespectacled supporter asked about the health of one particular senior citizen: Sanders himself.


“Getting a little tired, but you would too,” Sanders practically yelled, lifting his arms for a shrug as the voters in front of him laughed and cheered. “I’m feeling good.”

In a normal political universe, a heart attack befalling the oldest candidate in a race would mark the beginning of the end of their candidacy. But nothing about Sanders’ rise in politics has been normal, and he has — improbably — managed to emerge from the health crisis with higher poll numbers and more momentum than he had before.

The development has further scrambled the top tier of an increasingly unsettled Democratic primary race, and poses a renewed threat to Senator Elizabeth Warren, who appeared to be locking down much of the party’s liberal wing when Sanders’ polling was lagging over the summer and early fall.

During the past three weeks, Sanders has secured key endorsements from liberal stars like Representative Alexandria Ocasio-Cortez and sprinkled a busy campaign schedule with major rallies. Far from deflating his ambitions, it seems Sanders’ heart attack added a new — and more personal — dimension to a campaign that has been criticized for lacking warmth.

“I think the heart attack humanized Bernie Sanders,” said Aimee Allison, the founder of She The People, a progressive group focused on women of color whose members have given Sanders a prickly reception in the past. “He reminded a lot of people who he is as a person.”


A Monmouth poll taken last week showed Sanders at 20 percent support nationally, behind former vice president Joe Biden and Warren, who were tied at 23 percent. Since the last Monmouth poll in September, Sanders had gained five points — and Warren had lost the same amount.

Now, as she absorbs repeated attacks from moderates, including Biden and South Bend, Ind., Mayor Pete Buttigieg, Warren also has to worry about her left flank.

Even Sanders’ own campaign acknowledges Warren’s rough turn in the spotlight has helped him. He has never put out a detailed plan to pay for his signature policy idea, Medicare for All, but he has largely escaped incoming fire as moderate candidates castigate Warren for hers.

“I think we’ve always benefited as a campaign from the credibility of being the ones who wrote the damn bill,” said Faiz Shakir, Sanders’ campaign manager. “People are making a determination of who’s going to fight for this change, and who do we trust to take this over the finish line?”

Jim Zogby, a board member of the Sanders-aligned group Our Revolution, made the sentiment plainer. “As he starts to get more attention his numbers are going to go up. And they’re not going to come from Amy Klobuchar,” he said. “They’re going to come from her.”


Before his Oct. 1 heart attack, Sanders led the field in grass-roots fund-raising, but Warren was climbing well ahead of him in most national polls. The campaign also announced a staff shake-up in New Hampshire, prompting speculation that he was in trouble. Many pundits assumed the heart attack was a death knell for a campaign dependent on the candidate’s insurgent energy, and early polling bore that out.

But his allies say it also touched off a subtle shift. Unlike Warren, who talks extensively about the financial stresses of her childhood in Oklahoma — and her father’s heart attack — Sanders had spoken little of his working class upbringing in Brooklyn. But his heart attack has brought his personal story back to the fore, burnishing his status as a scrappy and endearing underdog.

To Sanders’ supporters, who often complain that their candidate doesn’t get his due from the press and the Democratic establishment, it was galvanizing. “It just made myself and many others with whom I’ve spoken more determined that he not only get back in, but that we do whatever we can to help him over the line,” Zogby said.

Among those supporters was Ocasio-Cortez, the superstar from New York and fellow Democratic socialist. She told NPR that she called Sanders while he was in the hospital.

“I think for me, that moment was just a gut check,” Ocasio-Cortez said, adding, “that was a moment that it became very clear to me that I wanted to be part of a mass movement of working class Americans, and I wanted to be part of that as soon as I could.”


Ocasio-Cortez endorsed Sanders last month, and their joint October rally in Queens — which drew 26,000people — sent a message that the candidate who upended the 2016 Democratic primary was not going anywhere.

Sanders has also attempted to leverage the roiling debate over Medicare for All to his benefit by casting himself as a liberal fighter who is willing to raise taxes for something his supporters want. Warren’s 20-page, $20.5 trillion plan to fund the program would not raise taxes on the middle class.

Sanders has never released so detailed a Medicare for All funding proposal, but he has spoken about levying a 4 percent income tax to pay for it — a point some liberals have embraced.

“He doesn’t mind talking about the fact that, of course, we’re gonna pay for this with taxes,” said Arnie Arneson, a liberal talk show host in New Hampshire “It’s really easy to talk about taxing billionaires — it’s a lot harder to talk about how we all have to be invested in this.”

Warren’s supporters have praised her willingness to drill down on the details of Medicare for All. And she has several advantages over Sanders, who has yet to prove he can grow his support beyond his hardcore base. Her campaign events are full of voters who supported both Sanders and Hillary Clinton in 2016, and she has done more to build trust with the Democratic Party even though she casts herself as an outsider. This week, she announced the endorsement of Massachusetts Representative Ayanna Pressley, her highest-profile surrogate of color yet, and was endorsed by a group of 100 black female activists.


Warren has also cut into Sanders’ lead among young voters. A poll of 18-to-29 year-olds from Harvard’s Institute of Politics found Sanders had 28 percent support from that group, with Warren six points behind — but she had gained 18 percentage points with that group since the spring.

During her last two trips to Iowa, Warren made a point of stopping at colleges and universities. On Monday, students squeezed into an event space at Grinnell College to see her joke about climate-change deniers and call for the cancellation of student debt. There, and at other events for both her and Sanders over the weekend, many voters said they were still deciding between the two of them.

Among them was Molly Jennings, 51, who saw Warren speak in Vinton, Iowa, and said her top three choices were her, Sanders, and Buttigieg. Sanders’ reaction to his heart attack, she said, had deeply impressed her.

“He didn’t, you know, wring his hands and say, ‘Oh my God, I’m just, I’m not well I can’t do this,’ ” Jennings said. “He jumped right back in.”

Jess Bidgood can be reached at Jess.Bidgood@globe.com. Follow her on Twitter@jessbidgood. Liz Goodwin can be reached at elizabeth.goodwin@globe.com. Follow her on Twitter @lizcgoodwin