At first glance, Dave Stanlake and Maurice Fields don't seem to have a lot in common.

Stanlake, 70, lives in Coon Rapids and is a retired manufacturing materials director. Fields, 21, is from Milwaukee. He'll graduate from St. Paul's Concordia University in December and plans a career as an opera singer.

But when it comes to politics, they agree: Some 2020 presidential candidates are too old for the crucial, taxing job.

"The thing I have trouble with is the fact that as you get older and more stuck in your ways, the less you are likely … to actually change and be able to listen to people," Fields said. He wants a president who is "really hip to the jive."

Stanlake isn't interested in candidates who are pushing 80 and said the next president should be in his or her 50s, 40s or even 30s because they "are better equipped physically and emotionally to deal with the hardships of that office."

President Donald Trump, who will be 73 next month, is the nation's oldest chief executive. Four candidates trying to replace him — former Vice President Joe Biden, Sens. Bernie Sanders and Elizabeth Warren and former Massachusetts Gov. William Weld — would inherit the oldest-ever title. Sanders, 77, is the most senior.

Four Democrats would be the youngest president in history: South Bend, Ind., Mayor Pete Buttigieg and U.S. Reps. Tulsi Gabbard, Seth Moulton and Eric Swalwell. Buttigieg, the youngest, is 37.

An NBC News/Wall Street Journal poll conducted earlier this year found that 37% of registered voters were enthusiastic about or comfortable with a candidate 75 or older; 58% said they felt that way about a candidate younger than 40.

Interviews with people at the Coon Rapids Senior Center and with students and recent graduates at Concordia defied stereotypes: Some older people fret about the risks of septuagenarian presidents and some younger people want a mature chief executive.

"I personally would like a president that's older," said Huldah Philips, 18, who's from Woodbury and entering her junior year studying international business. Employers making a hiring decision wouldn't want "a newbie," she said. "You would want someone that has experience and is qualified."

Mitch Zillman, a 22-year-old from Marshfield, Wis., is headed to law school and considers climate change a top issue. He has more confidence in younger candidates to tackle it: "I've met many older people who don't really feel an obligation to do anything about it."

On the other hand, he respects the knowledge that comes with experience and worries that some younger candidates can be "very rash and a bit over-passionate."

Age isn't a decisive factor for Sophia Spear, 17, a student at Centennial High School in Circle Pines who takes all her classes at Concordia.

"It would be nice to see some younger people [running]. I think that would motivate youth to get involved in politics," she said. "But I understand why a lot of politicians are older. … I think experience helps."

Anoka resident Kathy Gunerius, 78, has "no problem at all" with an older candidate if they're in good health. She also worries "a little bit" about younger candidates who might lack life experience. "It's really important that we have a mixture" of ages, she said.

Glenda Meixell, 74, won re-election last year to a four-year term as an Anoka County conservation supervisor after concluding that "I am feeling good and there's something to be said for '70 is the new 60.' " She added that she'd step down if she became impaired.

Coon Rapids stroke survivor Bob Keegan, 74, noted that a serious illness "can just come out of nowhere." He doesn't think age should necessarily be a factor in the campaign, but he wants "fresh faces and fresh ideas."

No candidate should be disqualified on the basis of age, said Mark Fisher, a professor of neurology and political science at the University of California, Irvine. But it "can be an issue that would encourage … heightened scrutiny of a candidate's mental and physical facilities," he said, calling it "a legitimate issue and focus."

It's likely that Ronald Reagan had symptoms of Alzheimer's disease during his final years in office, Fisher said.

Neurodegenerative processes like Alzheimer's and cerebrovascular diseases that affect cognition should be assessed in older candidates and release of medical records should be required, he said.

Trump's reluctance to do so could "lead to a boomerang effect," and future candidates "will not be able to run without releasing them," said Richard Pacelle, head of the political science department at the University of Tennessee, Knoxville. He expects strong 2020 turnout by younger voters but warned that "group politics and identity politics have as many negatives as positives."

The median age of U.S. presidents is about 55, "which is about right," said David Woodard, 64, who teaches history and political science at Concordia. He's rooting for a younger woman to advance.

Concordia senior Amy Stone, 28, who's from Plymouth and majors in management leadership, thinks a younger president would work harder to safeguard her retirement funds. Omaha native Tyler Dunn, 22, likes the idea of an older nominee and a younger running mate. He just graduated and wants to work on Washington's Capitol Hill.

Bob Powell of Ramsey, who is 87, also wants an older president. Younger candidates "ought to try Congress or something first and work up from there," he said.

But the prospect of one of the oldest candidates winning makes Janet Harvey "a little nervous." She's 67 and lives in Coon Rapids. "As awful as this sounds," she said, Sanders' age "bugs me enough so that I'm not interested in him at all."

There's a generation gap separating senior Brooke Steigauf, 21, an art education major from St. Paul, and Lori Anderson, 61, of Coon Rapids.

Steigauf's ideal president is "someone that's older who has the mind-set of a younger person in the sense that they're able to seek new experiences, new perspectives," she said.

Not Anderson. "I'm tired of being legislated by old white men," she said. "I need somebody in the White House who knows what it's like to live in the trenches."

Judy Keen • 612-673-4234