He has taken to calling himself “the retirement guy,” after introducing a plan this week for long-term care.
He recently referenced the “Bull Moose progressive movement,” a nod to the politics of Teddy Roosevelt.
As Mr. Buttigieg, 37, looks to solidify his support in the remaining weeks before the Democratic primary season begins, he has found a wellspring of enthusiasm among a critical bloc of voters more frequently associated with Joseph R. Biden Jr.: older white Americans.
With Democrats and party officials worried that Mr. Buttigieg’s inexperience could hurt his chances against President Trump in the general election, his ability to connect with these voters provides a counterpoint to the criticism that he is too young to win next November.
This demographic has also become a crucial pillar of support for a candidate who has almost no backing from African-Americans and who lags some of his rivals with young voters. Older Americans are among the most reliable groups of voters for presidential candidates, especially in early nominating states like Iowa, New Hampshire and South Carolina.
Their support helps explain why Mr. Buttigieg, whose only governing experience is as the mayor of South Bend, Ind., has joined Mr. Biden, Elizabeth Warren and Bernie Sanders, all Washington veterans, in the top tier of candidates.
During a burst of campaign stops in Iowa this week, his first trip to the state since a Des Moines Register/CNN poll showed him with a commanding, nine-point lead here, Mr. Buttigieg repeatedly made appeals to older Iowans that were hardly subtle.
“We’ve got to act not just to shore up Social Security but to make sure everybody can retire and live in dignity,” he said at a rally on Monday evening in Council Bluffs, Iowa. “Call it my ‘Gray New Deal.’”
His message appears to be resonating in the two, predominantly white states that vote first for the nomination. In Iowa, 28 percent of likely Democratic caucusgoers 65 and older supported Mr. Buttigieg, according to the Register poll; that puts him ahead of Mr. Biden, who had dominated the group with 35 percent support in September. Mr. Buttigieg has also edged past Mr. Biden in New Hampshire, the first primary state, and now leads the field among voters over 65, with 17 percent, according to a Suffolk University/Boston Globe poll this week.
“He reminds everyone of their favorite grandson,” said Sean Bagniewski, the Democratic chair in Polk County, which includes Des Moines.
John Grennan, the Democratic chair in Poweshiek County, Iowa, said Mr. Buttigieg was framing his pitch to older voters in a compelling and empathetic way, particularly when he speaks about retirement security and how it affects his parents’ generation.
“I have to think that some older voters see Pete as the son they’d want to have — very smart, respectful of traditional institutions like the church and the military, and relentlessly cheerful and optimistic about what America can be,” Mr. Grennan said.
His success with older Iowa voters less than 10 weeks before the caucuses is also partly attributable to how ubiquitous he has become here. Several caucusgoers said they had seen him on television, in interviews and debates, and more recently, in ads. Since September, he has blanketed the airwaves in the state, which could be helping him with older voters who are more likely to be watching television without skipping commercials.
Art Cullen, the Pulitzer Prize-winning editor of The Storm Lake Times in northwestern Iowa, said he thought Mr. Buttigieg was appealing to older Iowans because they were “impressed with his brains” and because he came across as “polite.”
“Castro kind of comes off with fangs every now and again, as he did with Biden and Beto — Buttigieg just doesn’t do that,” he said, a reference to Julián Castro’s debate-stage attacks, which backfired. “I think that probably appeals to older Iowans’ sense of decorum.”
In a brief interview before an event in Storm Lake on Tuesday, Mr. Buttigieg theorized that he was attracting older Americans because they might have “a more generous understanding of what experience means.”
“Every older person was a younger person once,” he said. “And maybe it demystifies a little bit the extent to which age represents readiness.”
At the same time, Mr. Buttigieg is struggling to attract voters on the opposite end of the spectrum — those closer to his own age. At all of his events in Iowa, even the rally in Council Bluffs, which was held at a high school, older people made up a sizable portion of Mr. Buttigieg’s crowds, providing a striking contrast: a fresh-faced mayor of a midsize city speaking to silver-haired attendees.
Asked in the interview why he was having more trouble connecting with younger voters, he pointed to their “strong sense of impatience about the changes that need to come and the extent to which it feels like they’ve grown up in an America that just tolerates the intolerable.” But he said he was also working to convince young people to come around to his more tempered vision for change.
“The case I’m making is that my proposals are plenty big,” he said.
Older voters who support Mr. Buttigieg say he represents the best hope for the country, offering a future-focused vision that they feel will help younger generations. They often cite his intelligence, his plain-spokenness and his military service as reasons he is now a top choice even if they knew little of him just months earlier. And of those who mention his sexuality at all, they often treat it with a shrug.
“We should tilt toward somebody a little more in touch with the issues that are really, really important to the 40s and under,” said Bill Horner, 79, who came from his farm in Red Oak, Iowa, to see Mr. Buttigieg at an event on Monday morning. “They’re the ones who have the longest time in this country.”
Martha Berry, 72, of Mount Ayr, Iowa, said Mr. Buttigieg “looks like he’s really well put together and a well-rounded young man,” favorably comparing him to John F. Kennedy.
“Young Kennedy was just barely of age to come into the presidency,” she said. “And he did a great job.”
If younger Iowans often gravitate toward Ms. Warren’s message of “big, structural change” or to Mr. Sanders’s call for “political revolution,” some older Iowans point to Mr. Buttigieg’s more moderate positions, like his support not for “Medicare for all” but for “Medicare for all who want it.”
Still, some older Iowans, even those who were excited about his candidacy, expressed discomfort with his age and lack of political experience. Should he be elected, he would be the youngest president ever.
“I wish he had a little more experience — my only sticking point is, gosh, he’s young,” said Lisa Faurot, 59, of Council Bluffs. Asked whether she considered his age a drawback, she said she did. “I would say that’s a downside,” she said. “But on the other hand, Obama didn’t have a lot of experience.”
Yet with his optimistic message and frequent nods to his Christian faith, Mr. Buttigieg has also struck a deeply personal chord.
Gordon Reisinger, 79, who works in the cattle business, said before Mr. Buttigieg’s event in Red Oak that he and his parents had long been Republicans but Mr. Trump’s election profoundly shifted his views. Now, he is considering Mr. Buttigieg because “he would move our country forward.”
“I think with somebody like Pete, it gives our grandchildren a chance to live in America in a free country like we have most of our time,” he said.
Before an event in Denison, as a snowstorm that threatened Thanksgiving travel loomed, Rick Crampton, 63, of rural Kiron, Iowa, said he had been especially impressed with Mr. Buttigieg after seeing him during the debates.
But his wife, Carol, 60, quickly interjected to provide a more succinct explanation: “He reminds us a ton of our son.”