WASHINGTON (AP) — Bestselling self-help author Marianne Williamson, who brought quirky spiritualism to the 2020 presidential race, has announced she's running for president again, becoming the first major Democrat to challenge President Joe Biden for his party's nomination in 2024.

Williamson, 70, is formally kicking off her campaign with an event in Washington on Saturday. Without mentioning former President Donald Trump, she noted in a weekend Facebook post that his unconventional White House win makes it "odd for anyone to think they can know who can win the presidency."

"I'm not putting myself through this again just to add to the conversation," Williamson wrote. "I'm running for president to help bring an aberrational chapter of our history to a close, and to help bring forth a new beginning."

Williamson running against a sitting president from her own party would be the longest of long shots under any circumstances. But that's especially true this cycle, as the Democratic establishment — and even potential presidential hopefuls who could have competed with Biden from the left or middle — has closed ranks with remarkable uniformity behind the president.

Williamson says she plans to follow her Washington announcement with travel to states voting early in the Democratic primary. That includes New Hampshire, where she's suggested she'd participate in the state's primary if it defies Democratic National Committee rules and holds the nation's first presidential nominating contest despite the party making South Carolina its leadoff state for 2024.

"I feel my forty years being up close and personal with the trauma of so many thousands of individuals gives me a unique perspective on what is needed to help repair America," Williamson wrote. "We need a politics that treats not just symptoms, but cause. That does not base itself on the crass imperatives of endless corporate profit, but on the eternal imperatives of our principles and values."

Biden hasn't yet announced a formal reelection bid that aides say is likely to come in the next few months. First lady Jill Biden recently told The Associated Press that there was "pretty much" nothing left for the president to do but pick a time and place to announce his reelection bid. Biden himself, though told ABC that "there's too many other things I have to finish in the near-term before I start a campaign."

A spiritual adviser to Oprah Winfrey and purveyor of physic memorabilia online, Williamson spent about a year seeking the Democratic presidential nomination in 2020.

One of her signature proposals was a plan to create a U.S. Department of Peace. She also advocated that the federal government pay massive financial reparations to Black Americans as atonement for centuries of slavery and discrimination.

She suspended her campaign in the weeks before 2020's leadoff Iowa caucus and later endorsed Vermont Sen. Bernie Sanders' 2020 bid. He finished second in the Democratic primary against Biden.

The author of more than a dozen books and an unsuccessful independent candidate for Congress from California in 2014, Williamson first made a name for herself on the national political stage during the 2016 presidential race. That's when she was a vocal support of Sanders' progressive challenge of eventual Democratic nominee Hillary Clinton.

This time, she evoked a theme Biden used frequently before last fall's midterm elections, when Democrats showed surprising resilience. The president argues that American democracy is under threat from extreme "MAGA Republicans" loyal to Trump's Make America Great Again movement. Williamson said the nation's political traditions may not endure today's threats.

"If we don't preserve the blessings of democracy today," she wrote in her Facebook post, "we should expect the threat of authoritarianism later."