They have stories of bachelorhood, divorce, remarriage, stepchildren and widowhood. The Democratic 2020 candidates for president offer a glimpse of the modern American family – and could produce the first first gentleman in the country’s history.

Contenders’ spouses and partners are about to be thrust into the political limelight and come under close scrutiny as the primary races towards the first voting for the party’s nominee, in Iowa and New Hampshire early next year.

Three years after hopes that Hillary Clinton’s husband, the former president Bill Clinton, would make history by taking on the role of first gentleman were shattered by Donald Trump, two of the four candidates in the Democratic top tier are married to men.

The South Bend Mayor Pete Buttigieg, 37, is married to Chasten Buttigieg, a 30-year-old teacher, aiming to become the first openly gay spouse in the White House.

“I could be the first man in history to pick out the White House china,” Chasten quipped at a dinner held by the Human Rights Campaign.

Same-sex marriage was only legalised across the country in 2015. Some 61% of Americans support same-sex marriage, up from 31% in 2004, according to the Pew Research Center. But the prospect of the Buttigiegs dancing together at the inaugural ball would not be universally popular in the conservative heartlands.

Chasten would be likely to use the position to promote causes such as arts and education. He has already proved a breakout star of the election campaign, phone-banking and making speeches at fundraisers.

Chasten, who also dabbles in improv, has nearly 400,000 followers on Twitter, posting behind-the-scenes photos from the campaign, including updates on the couple’s dogs: Truman, a labrador-beagle mix, and Buddy, a puggle with one eye.

In April he tweeted wryly: “Friends: omg your campaign life must be so glamorous how exciting! Me: no, yeah, the pretzel dog or $7 LGA airport chili served in a coffee cup is the height of luxury.”

Eric Marcus, the founder and host of the Making Gay History podcast, said: “There are people for whom any public display of affection between Pete Buttigieg and his husband is mind-blowing and upsetting. That said, even some of the reddest conservatives have LGBTQ people in their families and have made enormous strides.

“I wouldn’t underestimate the capacity of Americans to accept that relationship if Mayor Buttigieg became President Buttigieg. Lots of people were sceptical about Michelle Obama as an African American first lady.”

He called the Buttigiegs devoted and “a classic American love story … as normal and traditional [as] what we’ve come to expect of presidents and their spouses.

Bruce Mann pats a dog while his wife, Elizabeth Warren, speaks at a campaign event in Hanover, New Hampshire. Photograph: Elise Amendola/AP

The other leading first gentleman contender is at the opposite end of the age and demeanour spectrum. Bruce Mann, 69, a professor at Harvard Law School, is the husband of Senator Elizabeth Warren, who was previously married (she has two adult children).

The couple married in 1980. Reflecting on their early life, in her memoir, Warren wrote: “Bruce quietly took over most of the cooking.”

For his part, Mann told the MassLive website in 2012 he never expected fame or glory. “We have each had academic careers for roughly 35 years,” he said. “This is not something we ever aimed for, ever thought about, ever expected.”

He made a fleeting appearance in his wife’s campaign launch video and has been seen looking after their recently acquired golden retriever, Bailey.

Senator Amy Klobuchar’s husband, John Bessler, was raised in Minnesota like her. They met in a pool hall, married in 1993 and have one daughter, Abigail. Bessler is a legal scholar who teaches at the Georgetown University Law Center and University of Baltimore. He has published several books about capital punishment.

Congresswoman Tulsi Gabbard of Hawaii, another divorcee, is married to Abraham Williams, a film-maker who has produced some of her past campaign adverts. His Twitter bio states: “Cinematographer, Camera/ Steadicam Operator, Photographer, and Surfer. Proud husband and #1 fan of @tulsigabbard.”

The couple were married by a Hindu priest in a Vedic ceremony in 2015. Gabbard told the New York Times that Williams proposed during a sunset surf.

Jane Sanders speaks at a rally at Queensbridge Park, New York, for the campaign of her husband, Bernie Sanders. Photograph: Erik Pendzich/Rex/Shutterstock

Only two presidents have been divorcees: Ronald Reagan and Donald Trump. That might change after 2020.

Like Warren, Senator Bernie Sanders of Vermont has been married before: for two years in the 1960s. He remarried in 1988, taking his bride, Jane, on what he has called “a very strange honeymoon” to the Soviet Union.

Jane, who has been a social worker and college administrator, has worn many hats as Sanders’ administrator, adviser, policy expert and spokeswoman. At his 2020 campaign launch in New York, the 69-year-old said: “I feel honoured to be his wife, and I know that might not be politically correct to identify myself as ‘a wife’, but it’s one of the greatest honors of my life.”

The Democratic frontrunner, Joe Biden, was widowed in 1972 when his wife, Neilia, and baby daughter, Naomi, were killed in a car crash. Biden fell in love with Jill Jacobs, a teacher, and remarried in 1977. Jill served as second lady during her husband’s tenure as vice-president under Barack Obama, working with military families while also teaching full time at Northern Virginia Community College.

She has been actively campaigning for her husband’s 2020 bid at fundraisers and other events, though not without odd occurrences: as she delivered a speech at a rally in early December, Joe leaned over and sucked one of her fingers.

Senator Cory Booker of New Jersey has never been married – once almost unthinkable for a presidential candidate. But he is dating the actor Rosario Dawson, star of films including Rent and The Lego Batman Movie. The couple say they speak almost every day, with Booker reading books to Dawson over the phone live or on voicemail. She recently campaigned for him in Iowa.

Rosario Dawson with Cory Booker after the Democratic presidential debate in Westerville, Ohio, in October. Photograph: Matt Baron/Rex/Shutterstock

The New York Times reported earlier this month: “On top of a busy professional schedule, she has been helping her 62-year-old father through surgery for pancreatic cancer. ‘This stuff is intense. It’s really strenuous,’ she said. “And it’s so public all the time, that there’s a really beautiful intimacy somehow that we’ve created and maintained on this journey that’s been really important for me going through this personal journey.’”

Andrew Yang met his future wife, Evelyn, a former marketing manager at L’Oréal, on the campus of Columbia University in New York. “He seemed so earnest and genuine,” she told the Washington Post. “I felt like he wore his heart on his sleeve, which was refreshing. I joke with him, now even, it’s like he had no game. He wasn’t trying to game it in any way, and I really love that about him.” The couple married in 2011 and have two sons.

Of all the candidates’ other halves, only one will get a shot at the White House next year. The rest will find themselves cast in the role of Doug Emhoff, husband of the Senator Kamala Harris of California, who abruptly quit the race in early December, leaving him to offer what comfort he could. “I’ve got you,” he tweeted, “As always.”