MANCHESTER, N.H. — Republicans have nominated a candidate older than his Democratic counterpart in every presidential election since 1968 but one — the GOP's last victory, in 2004. This campaign, the idea of a younger candidate against Democratic front-runner Hillary Clinton offers both symbolic and strategic appeal for Republicans.
Television personality Donald Trump, 69, continues to top national primary polls. But two of the candidates who have demonstrated the most momentum of late are more than two decades younger: Marco Rubio and Ted Cruz, both 44, potentially offering a stark contrast with Clinton, 68, who, if elected, would be the oldest president to take office since Ronald Reagan.
That contrast is part of the reason Rich Manney, a 68-year-old Goffstown retiree, has narrowed his candidate list down to four: Governor Chris Christie of New Jersey, Rubio, Cruz, and Trump.Only Trump is older than 53.
"The people that are there now — the establishment doesn't seem to be helping us out any," said Manney, a Navy and Coast Guard veteran. Of his preference for Rubio and Cruz, he said, "I think because they're fresh, they're a fresh look."
In the early states on the presidential nomination calendar, older voters play a larger role than in the fall general election. Exit polls showed that in the 2012 New Hampshire GOP primary, 69 percent of voters were 45 or older. In the Florida GOP primary, voters 45 or older made up 78 percent, and nearly half of those were 65 or older.
At the same time that Rubio and Cruz have been making strides in primary polls, candidates with longer resumes, such as former Florida governor Jeb Bush, 62, and Ohio Governor John Kasich, 63, have been trapped in the single digits for months.
Clinton provided voters with a reminder of her age during a debate last month, noting, "I come from the '60s, a long time ago." Rubio's campaign responded by releasing a Web ad with the clip entitled "This election is a generational choice."
In the general election, the Republican electorate skews older than its Democratic counterpart. In 2012, when President Obama faced Mitt Romney, exit polls showed that voters age 65 and older — who accounted for 16 percent of the total electorate — broke for Romney at a 56 percent clip. Fifty-one percent of voters between ages 45 and 64, a group that made up 38 percent of the overall electorate, went Republican.
Historically, that dynamic has provided Democrats with an opening to push a sales pitch premised on generational change. Beginning in 1980, the average age of Republican presidential candidates on Election Day has been just over 66 . Over the same span, Democratic nominees have averaged under 53.
In 1996, President Bill Clinton, who turned 50 that year, bested Senator Bob Dole, who turned 73, in part by promising "a bridge to the 21st century."
Twelve years later, Obama, a first-term senator then age 47, argued for "change we can believe in" against Hillary Clinton during the primaries and for "change we need" against Republican John McCain, then 72 and in his fourth Senate term, in the general election.
This year, the Democratic nominee appears likely to come from the front wave of the baby boom generation, with Clinton born in 1947, or beyond, with Senator Bernie Sanders of Vermont born in 1941.
Clinton's age is somewhat offset among progressives by her gender. While youth is not in her favor, the prospect of electing the first female president appeals to many of her party's voters.
For years, Republicans have been crafting the message Clinton's wealth and remove from everyday burdens shouldered by most Americans have rendered her out of touch.
"Under no circumstance would I suggest that she is too old for anything, but she has been so entrenched in Washington for so long that it is hard for her to make the argument that she is a new messenger for anything," said New Hampshire GOP chairwoman Jennifer Horn.
Some Republican strategists think the prospect of an early baby boomer Democratic nominee would help the GOP overcome its image as the party of the aging white male, a dilemma addressed in the party's official postmortem report following Romney's 2012 loss to Obama.
But that line of strategic thinking may not extend to the broader primary electorate.
"Voters don't go into the booth saying, 'Hey, I'm voting for generational change.' They're voting only for their concerns and their own values," said David Carney, a New Hampshire-based Republican consultant. "I don't believe voters ever go into the voting booth based on political rationale."
Still, Rubio has used at least an implicit argument for youth not just against Clinton, but also against his elders within the crowded GOP primary field. At the Nov. 10 debate in Milwaukee, Rubio used the term "21st century" no fewer than seven times, according to a review of the transcript, and promised, "If I am our nominee, [Democrats] will be the party of the past, we will be the party of the 21st century."
While they are the same age, Rubio has pressed a more youth-based argument than Cruz, who has centered his strategy around appealing to conservatives and evangelicals. The two senators share Cuban roots, allowing them to complement their age-based pitch with the ethnic diversity that some GOP strategists say is crucial to the party's long-term success.
Horn said she had detected a yearning for generational change within the party "whether I'm talking to voters or talking to candidates, and I think we see it in the way our candidates are campaigning."
"They're looking for energy and inspiration and a new path, a new direction," she said.
Jim O'Sullivan can be reached at jim.osullivan@globe.com. Follow him on Twitter at @JOSreports.