Nicole Gaudiano

USA TODAY

MANCHESTER, N.H. — Sen. Bernie Sanders has already shown he’s a hit with young voters, but the 74-year-old Vermont independent will have to work to win over his contemporaries.

Iowa caucus entrance polls show Democratic front-runner Hillary Clinton was heavily favored by the 45-and-older set. And in New Hampshire, where Sanders is favored to win Tuesday's primary, Clinton supporters in that voter-rich age range say Sanders wouldn't be able to make good on his “pie in the sky” promises if elected. They're more impressed with Clinton's realism and foreign affairs experience.

They also like the former secretary of State's so-called “establishment” connections and her potential to become the first female president.

“He’s a nice person who has a lot of good ideas, but I don’t think they’re achievable,” Diane Zito, 75, a retired elementary school teacher from Bedford, N.H., and a Clinton volunteer, said of Sanders. “Hillary is more substantive, she’s more realistic, and she has by far the most experience.”

Phil Kirstein, 70, a mutual funds lawyer from Princeton, N.J., volunteering for Clinton in New Hampshire, said, “With the Congress, a lot of the programs that Sen. Sanders is espousing are going to be dead on arrival.”

Sanders says he's surprised he doesn't have stronger support from seniors, because there’s “nobody in the Senate who has fought harder” for them.

He long has opposed efforts to cut or slow the growth of Social Security benefits and he has introduced legislation to expand benefits by lifting the cap on taxable income above $250,000 a year. He also has introduced legislation that would allow Medicare to negotiate lower drug prices and let people import lower-cost prescriptions from Canada.

“We are going to focus on senior issues, and I think you’ll see us do a lot better in that age category,” Sanders said on MSNBC on Wednesday.

His campaign has worked hard to draw young people and first-time voters into the political process. In Iowa, Sanders bested Clinton by a stunning 84%-14% among 17- to 29-year-olds, according to The New York Times entrance polls. But Clinton topped Sanders 58%-35% among Iowans between 45 and 64, and even more decisively — 69%-26% — among those 65 and older, the polls showed.

Now, Sanders' campaign aims to expand his appeal to seniors — who are typically more likely to vote — by reminding them of his positions and record.

Sen. Bernie Sanders sees youth vote as key to campaign

Sanders plans to hold more town meetings with seniors and do more targeted advertising ahead of March 1 Democratic primaries in 11 states. Given his strong showing in Iowa — he trailed Clinton by only 0.3 points — Sanders says seniors and other voters may be ready to consider him as a serious alternative.

“Right now, we think we’re going to have a much bigger target universe in terms of voters,” said Tad Devine, Sanders’ senior media adviser. “We think seniors are going to be a big part of that.”

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This week, Sanders quickly responded to a progressive campaign to put candidates on record opposing any Social Security benefits cuts, then urged Clinton to do the same. She responded in a tweet to Sanders as progressives and Social Security advocates announced an online petition urging her to promise to block cuts.

“@BernieSanders I won’t cut Social Security. As always, I'll defend it, & I'll expand it. Enough false innuendos,” Clinton tweeted.

Lacy Crawford, of Social Security Works, noted that Clinton favors targeted increases in benefits while Sanders is proposing an “across-the-board” benefit increase.

“When I go around the country and speak to seniors, they let me know about how they are worried for their children and grandchildren, citing student debt and lack of pensions,” Crawford wrote in an email.

Some seniors in New Hampshire, however, don’t cite Social Security as a top concern. They believe — correctly or not — their benefits will be grandfathered in if the program changes.

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“It’s the younger generation who believes they’re not going to get it,” said Ernie Ketel, 72, a Sanders supporter from Rochester, N.H.

Ketel, who works at a mental health peer-support program, said he’s for Sanders because he wants campaign finance reform and a “Medicare-for-all” health care system, even though he’s nervous that Sanders may be “ahead of the electorate” on such issues.

Frank Zito, 71, an undeclared voter, said Sanders initially impressed him by speaking out against financial firms’ influence on government. Zito, a retired sales and marketing manager, had been leaning toward a vote for Sanders — or Ohio GOP Gov. John Kasich — but ultimately was won over by Clinton's clarity on foreign policy issues.

That pleased his wife, Diane, already a Clinton volunteer.

“I’ve got him on board,” she said. “I’ve got to get him working.”

Zito attended a rally for Clinton volunteers on Friday and told his wife he'd take down his Sanders yard sign.

“I want people to know we’ve made a decision, and we’re not getting a divorce,” he said with a laugh.

Follow @ngaudiano on Twitter.