While many of his rivals darkly warn that the country would never elect the snowy-haired, proudly cantankerous populist, Sanders argues that his brand of revolutionary progressivism is right for the moment. And his backers make the case that Sanders may be uniquely positioned to win back the White House for the Democrats by beating Trump at his own game: activating a passionate base of supporters built outside the traditional party system.

That’s the counterintuitive argument Senator Bernie Sanders and his boosters are making in the final days before voting begins in Iowa.

Is a 78-year-old self-described socialist, a man who vows to upend big chunks of the economy, raise taxes in a big way, and who — impolite but necessary to say — recently had a heart attack, really the Democrats’ best shot at beating President Trump?


“My Democratic Socialism says health care is a human right,” Sanders said at Tuesday’s debate, before ticking off his plans to raise the minimum wage to $15 and transition the country off of fossil fuels entirely. “That is what Democratic Socialism is about and that will win this election.”

His surrogates have drawn attention to head-to-head polls showing him besting Trump nationally and in key battleground states like Michigan and Wisconsin, where he often performs as well as the leader of the Democratic field, former vice president Joe Biden. And Sanders’ supporters point out that Trump’s campaign has begun targeting him on social media, a sign that the president may be taking him more seriously as a potential rival.

“He’s worried about Senator Bernard Sanders because he knows he cannot go head to head with him,” Sanders’ campaign cochair Nina Turner said this week.

But other Democrats, particularly those backing Biden, who has made his electability against Trump core to his campaign message, worry that Sanders could be a disaster for the party if he’s the nominee.


“Is Bernie right that his candidacy will produce more votes because there are some Sanders voters who won’t vote for anyone else?” asked former Pennsylvania governor Ed Rendell, who has endorsed Biden. “Yes he is. But that number is dwarfed by people who won’t vote for Bernie based on his positions.”

Rendell said Sanders’ Medicare for All plan, which would eliminate private health insurance in favor of a public system, and his plan to ban fracking, which is a booming energy industry in the battleground state of Pennsylvania, would lose him support in a general election.

Campaign staffers for moderate Democrats who defeated Republicans to win House seats in 2018 privately expressed concerns that Sanders being on the top of the ticket in 2020 could complicate their races. It would force them to spend time and money differentiating their policy stances from the Democratic nominee rather than focusing all-out on Trump.

“I think [Sanders winning the nomination] absolutely makes winning the most important states — five or six that will make the difference in 2020 — more challenging,” said Representative Dean Phillips of Minnesota, who won a seat in 2018 that Republicans had held since 1961. “Those are the states that matter. I wish people would turn a little bit more attention to that, and that’s why electability should matter more than ever.”

Democrats’ dislike of Trump has made electability the watchword of the 2020 race, as nervous voters carefully weigh who has the best shot at defeating him. With Sanders polling second to Biden nationally, neck-and-neck in Iowa, and ahead of him in New Hampshire, more voters and pundits are focusing on Sanders’ viability as a potential party nominee.


Chuck Rocha, a senior adviser to Sanders, said the campaign’s electability pitch is two-pronged. Sanders and his team, he said, are attempting to expand the electorate by motivating young people and people of color to the polls, and also by appealing to working-class Americans by positioning Sanders as the only candidate who voted down trade deals such as NAFTA while fighting corporate greed and the health care industry.

And although the 77-year-old Biden remains the most popular candidate among older black voters, Sanders has been able to attract young black and Latino voters like no other candidate, something that could help him win the general election if the young turn out in large numbers.

Political experts agree that some voters key to defeating Trump are more attracted to Sanders than some of his Democratic rivals, although some of those blocs do have a history of lower turnout than more traditional voters. A Morning Consult poll released last week found that Sanders outperformed Biden against Trump among voters under 30, self-described independents, and those who aren’t interested at all in politics, while Biden bested him among older and college-educated white voters.

“Bernie does have some strength in Trump quarters,” said Larry Sabato, a political scientist at the University of Virginia. “A lot of the working class who vote for Trump also say, ‘I like Bernie, he’s tough, he won’t back down.’”


But if Sanders became the nominee, that appeal could be outweighed by concerns among more moderate suburban voters who powered the Democrats’ midterm gains in 2018. Sanders doesn’t appear to be trying to win those voters at this point in his campaign, and a recent dust-up with his progressive rival, Senator Elizabeth Warren, suggests he believes they will swallow their concerns and vote for him, anyway.

Sanders’ volunteers reportedly were directed to tell voters backing Warren, 70, that her base of “affluent” supporters tend to show up at the polls anyway, while Sanders is attracting new voters into the party.

“We cannot nominate someone who takes big chunks of the Democratic coalition for granted,” Warren shot back last weekend. “We need someone who will bring our party together.”

If Sanders were to win the nomination, Republicans would also be sure to spend the election year labeling him a socialist who will dramatically raise taxes, which could hurt his electoral chances among older voters in particular. Although Trump campaign officials have acknowledged they will label any Democrat who becomes the nominee a socialist, Sanders actually is one, and the label remains political anathema in some quarters, such as the critical state of Florida, where many voters or their families fled repressive socialist regimes in Central and South America.

“Throughout much of the history of our lives, for people who are older, it was always a forbidden word,” said Kim Nalder, a professor of political science at California State University in Sacramento, of socialism. “For younger voters it doesn’t mean anything. But it will be a lot harder for him to get these older, more moderate American voters to swing around to him.”


Socialism is becoming more popular in America, however. A Gallup poll last year found that 4 in 10 Americans now have a favorable view of some form of socialism, largely based on the European model of more robust social welfare programs. That’s the version of democratic socialism that is more in line with what Sanders sells on the campaign trail.

And Sanders’ most ardent backers argue that the fact that he inspires strong feelings among voters — both good and bad — may actually mean he is more electable than a more middle-of-the-road candidate who neither angers nor excites people. They fear that a milquetoast moderate will be no match for Trump, who is passionately disliked by many but also has a fervent base of supporters.

“We understand that President Trump has a movement behind him, he has a movement of people rooted in white supremacy, rooted in exclusion" of people of color, said Jennifer Epps-Addison, president and co-executive director of the progressive Center for Popular Democracy Action, which has endorsed Sanders. “We need a Democratic candidate who inspires people, engages them, and brings them together.”

This is the argument that Sanders’ boosters are making against his chief rival, Biden. Last week, Politico obtained a script for Sanders volunteers that directed them to make the argument that Warren is not bringing new people into the Democratic Party and that Biden isn’t exciting voters.

“The problem is, no one is really excited about him,” the script said of Biden. “He doesn’t really have any volunteers and has no support at all among young people.”

Sanders’ supporters are famously devoted to him, with polls showing that more of his backers are enthusiastic about and committed to him than are the core supporters of his rivals.

“I’m just like, ‘Bernie all the way,’ ” said Cecilia Sileo, a 17-year-old high school junior who went to see Sanders speak at a town hall in Iowa City last weekend. “I just absolutely love him.… I’m not even thinking about another option.”

But Biden’s backers called into question this logic, arguing that the enthusiasm of supporters is not as important as their overall number. “If I go in and cast an enthusiastic vote for my candidate, how many votes does it count as?” Rendell said.

However, the Sanders team views motivating people to go to the polls, particularly younger Latino voters who have traditionally been less likely to vote, as core to its long-term general election strategy.

When Sanders launched his long-shot bid for the presidency in 2016, staffers and volunteers were typically drawn to his campaign for purely ideological reasons — not necessarily because they believed he could win. But his strong primary run against Hillary Clinton made many of his current operatives come to believe he had a real shot at the presidency.

This time, current and former staffers said, the campaign deployed on the basis of that belief, moving quickly to establish operational bases in key battleground states, and placing extra attention on reaching underserved and largely Latino and African-American communities, particularly in delegate-rich California. In Iowa, their first campaign mailers to caucus-goers were blasted out in Spanish.

“We want huge voter turnouts,” Rocha said. "That work takes longer, so that means we got there earlier and started building those relationships in those communities.”

Janet Drew, a 66-year-old retired registered nurse who drove from Maine to hear Sanders speak at a women’s rally Saturday in Portsmouth, N.H., she said she “absolutely” thinks he is electable.

“The Democrats who are running now have come up with plans he was proposing four years ago,” said Drew, wearing a Bernie pin and stickers fixed to her coat. “And age ain’t nothing but a number.”

Liz Goodwin can be reached at elizabeth.goodwin@globe.com. Follow her on Twitter @lizcgoodwin Reach Jazmine Ulloa at jazmine.ulloa@globe.com or on Twitter: @jazmineulloa