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Story highlights

The electability argument is likely to intensify ahead of Iowa and New Hampshire

Many Republicans say they view Clinton as a tougher general election match-up than Sanders

Watch CNN’s Democratic town hall, airing live from Iowa on Monday, 9 p.m. ET

(CNN) —  

Now 61 and retired, Jan Marcotte feels thrown back to her days as a high school political volunteer when she hears Bernie Sanders speak.

“I feel like if I close my eyes, I’d be back working for George McGovern,” she said after a Sanders rally last week.

That Sanders evokes memories of the 1972 Democratic presidential nominee, a pillar of American liberalism, helps explain his loyal following on the left. But while McGovern’s long-shot, grassroots campaign managed to upset a favorite of the stodgy Democratic establishment, the then-South Dakota senator went on to be crushed by a Republican who previously promised to awaken the nation’s working-class white “silent majority.”

President Richard Nixon won 49 states. McGovern won one.

It’s what could be the biggest challenge for Sanders, 74, in overcoming Hillary Clinton to win the 2016 Democratic nomination: Electability.

Despite his age, the self-described “democratic socialist” Sanders is a relatively fresh face on the national field, free from the years, even decades, of attacks that Hillary Clinton has experienced. That creates an opportunity for Republicans to try and define him – which causes some Democrats to worry about down ballot implications.

“Republicans would much rather run against Bernie Sanders and have a chance to define him from the get-go as extreme and out of touch,” Republican strategist Kevin Madden, a Mitt Romney campaign veteran, said Sunday on CNN’s “State of the Union.”

Monday town hall

The “electability” argument is likely to burst into the open Monday night in Des Moines, where Clinton and Sanders will both participate in a town hall hosted by the Iowa Democratic Party and Drake University and broadcast on CNN. In recent days, Clinton has emphasized her experience across a broad set of issues and her history of taking on Republicans, while Sanders has pointed to polls that show him outperforming Clinton.

Polls of hypothetical matchups between Democratic and Republican presidential contenders have shown Sanders doing better than Clinton against the GOP field. That gives the Vermont senator evidence to cite in swatting away concerns raised recently by Clinton and her allies that a Sanders nomination could wipe out President Barack Obama’s gains.

“One of the things that my opponent Secretary Clinton is saying is that Bernie is unelectable. He just cannot defeat a Republican candidate in a general election,” Sanders said last week in New Hampshire. “So it gives me some pleasure to give you some facts that that might just not be the case.”

He pointed to a new CNN/ORC poll that showed him crushing all Republican contenders in New Hampshire, while Clinton falls within the margin of error against most of them.

The Republican super PAC America Rising has assigned a tracker to follow Sanders on the campaign trail, and has submitted open-records requests for many of his documents.

Still, while polls tell one story, Republican campaigns and operatives tell another: They view Clinton as a much tougher general election opponent than Sanders.

A story by Yahoo’s Hunter Walker was an example of what could come up: Sanders’ one-time support for nationalizing industries like oil and electric utilities, the seizure of those industries without compensation and his desire to take the Rockefeller family’s wealth and use it to help the poor.

When CNN asked strategists working with Republican presidential campaigns how they might deploy those details against Sanders in a general election, none would discuss it on the record – another indication that the party is intent on letting Sanders remain unscathed while his opponent is Clinton.

Even the few swings Republicans are willing to take at Sanders are designed to undercut him on the left, too.

“A candidate that’s willing to shift to the middle as much as Hillary Clinton has proven she’s willing to is probably tougher in a general election,” Katie Packer, a veteran GOP operative who worked on Romney’s 2012 campaign, said on CNN’s “The Lead” with Jake Tapper last week.

Down-ballot impact?

It’s not just the presidency at stake: Democrats are hoping to pick up enough seats to retake control of the Senate in November, and narrow the GOP advantage in the House, as well.

The number two House Democrat said he is concerned about Sanders’ impact on candidates down ballot in 2016, complaining that Sanders lacks broad-based appeal.

“He calls himself a Socialist,” said House Minority Whip Steny Hoyer of Maryland, who backs Clinton. “I don’t think that’s a good title to be running for president of the United States. I don’t think that resonates well.”

Sen. Claire McCaskill, D-Missouri, a Clinton supporter, agreed.

“I think the Republicans would be very excited,” McCaskill told CNN. “They’re obviously helping him in every way they can. It tells everybody what they need to know.”

Sanders has pushed a major expansion of Medicare to cover all Americans as part of his platform, which he acknowledges would require tax increases. But Hoyer said the chances that Congress would approve such a plan are “very, very small.”

The same concerns are showing up on the campaign trail.

This week in Iowa, Jane Nettleton went to see Sanders at a campaign stop in Fort Dodge. She said she believes in many of his ideas, but is alarmed at how Republicans would define him.

“Those same Republicans that have been bashing Obama are just going to utter the word ‘communist’ instead of ‘socialist’ and that’s going to scare a lot of people,” Nettleton, who plans to caucus for Clinton, told CNN. “I think it would be political suicide, frankly.”

Stephanie Schulz, a 20-year-old University of Iowa student who supports Clinton, said she worries about what her Republican friends say about him.

“They say they don’t like Bernie Sanders because of his socialist policies,” she said. “I feel like that kind of scares people.”

Olivia Miller, a 20-year-old University of Iowa sophomore who is leaning toward supporting Clinton, called Sanders “overhyped a little bit because I think that some of the issues he has been talking about are too socialist.”

Among Sanders loyalists, though, the “socialist” tag is much ado about nothing.

“I’m not afraid of the word socialism. I know what it means. It’s not communism,” said Susan Stanbury, 72, a retired town manager from Peterborough, New Hampshire. “I believe that government has a role in taking care of its citizens.”

James Bragg, who was selling Sanders gear outside his campaign stop in Wolfeboro, New Hampshire, said the old notion of “communist behind a corner” is dying – and won’t concern Sanders’ younger supporters at all.

The socialist label, the 61-year-old Bragg said, is just “what the old people are afraid of.”

CNN’s Jeff Zeleny, Elizabeth Landers, Dan Merica and Deirdre Walsh contributed to this report. Bradner reported from Iowa City, Iowa; LoBianco reported from Wolfeboro, New Hampshire.