BOSTON >> President Joe Biden told campaign donors Tuesday that he wasn’t sure he’d be running for reelection if Donald Trump wasn’t also in the race, warning that democracy is “more at risk in 2024” and that the former president and his allies are out to “destroy” democratic institutions.

The president was using a trio of fundraisers to caution against what might happen should his predecessor again claim control of the White House, noting that Trump has described himself as his supporters’ “retribution” and has vowed to root out “vermin” in the country.

“We’ve got to get it done, not because of me. ... If Trump wasn’t running I’m not sure I’d be running. We cannot let him win,” Biden said, hitting the last words slowly for emphasis.

Biden’s forceful rhetoric came as Trump, the current GOP front-runner, who tried to overturn the 2020 election he lost and is facing criminal charges connected to those efforts, attempted over the weekend to turn the tables by calling Biden the “destroyer of American democracy.”

Biden, who said he is not alone in sounding the alarm over Trump, noted that Trump is the “only losing candidate” in U.S. history to not accept the results. Biden also said that on Jan. 6, 2021, as Trump supporters violently stormed the U.S. Capitol in a failed attempt to stop the certification of the election results, Trump sat in his dining room just off the Oval Office, “watching them threaten his own vice president.”

Biden also highlighted recent warnings about Trump from former Rep. Liz Cheney, R-Wyo., calling her a “powerful voice.”

“American democracy, I give you my word as a Biden, is at stake,” the president said at the first of three campaign fundraisers in the Boston area. Drawing some laughter from donors, Biden also mused: “He didn’t even show up at my inauguration. I can’t say I was disappointed, but he didn’t even show up.”

The warnings by Biden are increasingly part of his pitch to donors: that democracy is at stake if Trump were to win again and he must be defeated. The president is pushing to raise money for his reelection effort before the end of the year, appearing at seven events through Monday — with more to come. The events in Boston on Tuesday benefit his campaign and the broader Democratic Party.

They included an evening event in the city’s theater district featuring a concert by singer-songwriter James Taylor, who helped kick off a White House event in 2022 celebrating the Inflation Reduction Act, a climate and health care bill that Biden signed into law.

Onstage, Biden joked to the packed theater audience that he wouldn’t be long because he knew he was “the only thing standing” between the audience and the performance by Taylor.

“We’re always going to defend protect and fight for democracy,” he said. “That’s why I’m running.”

November was the campaign’s strongest grassroots fundraising month since Biden formally announced last April that he was seeking a second term, according to a campaign official who insisted on anonymity to discuss campaign finances before details are made public. The numbers will be released in January.

In October, Biden and the Democratic National Committee reported raising more than $71 million for his reelection in the three months ending Sept. 30, a sign that donors remained behind him going into the 2024 presidential race.

Biden had only political events on his public schedule for Tuesday, which is rare. Presidents who are running for reelection typically include an official event, like a policy speech, on the schedule to help defray costs for their campaign.

Biden will also attend a fundraiser Wednesday near the White House and another one Monday in Philadelphia. He’ll headline fundraisers in Washington, D.C., and in Maryland later in December.

On Friday, Biden will head to Los Angeles for a big-dollar event that will be his first since strikes by writers and actors effectively ground his fundraising to a halt in the heart of the entertainment industry, which has long served as a major source of campaign money for Democrats.

The event is slated to be at the home of Michael Smith, a celebrity interior designer who decorated the White House for President Barack Obama, and Smith’s partner, James Costos, a former HBO executive who was Obama’s ambassador to Spain. It is expected to raise millions of dollars and draw a crowd of celebrities. Rocker Lenny Kravitz is slated to perform.

Film director Steven Spielberg and his wife, Kate Capshaw, who starred in “Indiana Jones and the Temple of Doom,” are among the hosts of the event, as are recording industry mogul David Geffen, “Scandal” showrunner Shonda Rhimes and “This is Spinal Tap” director Rob Reiner, according to an invitation obtained by the AP.

Former House Speaker Nancy Pelosi, D-Calif., is also a co-host. Barbra Streisand is set to attend.

As of the last fundraising reporting deadline at the end of September, Biden and his party reported $91 million cash on hand. He is helped by the fact that as the party’s leader he has entered into a joint fundraising agreement with the Democratic National Committee, as well as state parties, which enables him to receive a check from a single donor that is in the range of $1 million.