Congressman Dean Phillips is running for president in the 2024 Democratic primary, becoming the only elected Democrat challenging President Biden.

In an announcement Friday, is Mr. Phillips pitching himself as a more electable alternative to Mr. Biden, saying, “If President Biden is the Democratic nominee, we face an unacceptable risk of Trump being back in the White House,” adding that he understands his campaign is a “long shot.”

“I didn’t set out to enter this race. But it looks like on our current course, the Democrats will lose and Trump will be our President again. President Biden is a good man and someone I tremendously respect,” Mr. Phillips said. “This is a last-minute campaign, but desperate times call for desperate measures, and courage is an important value to me.”

Mr. Phillips will be the only other elected official running in the Democratic primary. Activist Marianne Williamson is also seeking the nomination, though her campaign has failed to gain traction among Democratic voters. An anti-vaccine activist, Robert F. Kennedy Jr., who was running as a Democrat and polling in the low double digits, announced earlier this month he would seek the nomination as an independent.

While Mr. Phillips is a self-admitted “long shot” candidate, there are a few factors that might boost his odds. First, polling consistently suggests that Democrats have an appetite for a non-Biden candidate.

A recent CNN SSRS survey found that 67 percent of Democrats and 82 percent of Democratic-leaning voters would prefer a candidate other than Mr. Biden, with his age and health cited as the biggest reasons.

Another factor is that Mr. Phillips is almost certain to win the New Hampshire primary due to the state’s dispute with the Democratic Party over primary election calendar changes.

Democrats have rearranged their primary calendar to put South Carolina first. That primary will happen in early February. As a result, New Hampshire, which has refused to accept that it has lost its “first in the nation” status, will hold an unsanctioned Democratic primary in January.

Due to this dispute, Mr. Biden won’t appear on the New Hampshire ballots, and New Hampshire’s delegates at the 2024 Democratic convention at Chicago won’t carry any actual weight in deciding the nominee.

Still, a win at New Hampshire would be a symbolic victory for Mr. Phillips, though it’s not clear whether that might be able to catapult his campaign into victories elsewhere.

Mr. Phillips has brought on a veteran campaign manager, Steve Schmidt, to run his campaign. Mr. Schmidt has historically been a campaign manager for Republicans but announced he would register as a Democrat in late 2020 after airing grievances with President Trump and his brand of politics, telling MSNBC that the GOP is “no longer dedicated to American democracy.” 

He made a name for himself while feuding with Governor Palin when he worked for John McCain’s 2008 presidential campaign, which was memorialized in the HBO film “Game Change.” He was played by Woody Harrelson.

Mr. Schmidt first made national waves while managing Governor Schwarzenegger’s re-election bid in 2006, which was initially expected to fail due to Mr. Schwarenegger’s unpopularity at the time. The governor went on to win re-election with 57 percent of the vote.

In terms of messaging, Mr. Phillips has focused his campaign on three themes: affordability, public safety, and ushering in a generational change in leadership. He’s also promised to advocate for reforms he says will help lessen polarization.

“And finally, it will be about listening to each other to get back to a less divisive political environment,” Mr. Phillips said. “There’s government reform that will help with this too — we need term limits, campaign finance reform, and things like bipartisan cabinets.”