President Joe Biden has not yet formally launched a re-election campaign for 2024, though he is widely expected to eventually do so, and when that day finally comes Biden will find that he is not running completely unopposed for the Democratic Party's presidential nomination.

Robert F. Kennedy Jr. submitted the paperwork on Wednesday to officially declare himself to be a Democratic candidate for the presidency in 2024, Politico reported.

He will join spiritualist and self-help author Marianne Williamson as the only two prominent Democrats, at least thus far, to challenge the incumbent president to be their party's top nominee in the next election cycle.

Candidacy is now official

A formal "statement of candidacy" form was filed on Wednesday with the Federal Election Commission by the California-based Kennedy that officially declared himself to be a Democratic candidate for president and designated the Massachusetts-based Team Kennedy as his principal campaign committee.

That news was not entirely unexpected, as Kennedy had revealed about a month ago that he was giving serious consideration to launching a presidential campaign with a tweet that linked to his Team Kennedy website.

"If it looks like I can raise the money and mobilize enough people to win, I’ll jump in the race," he tweeted on March 10.

"If I run, my top priority will be to end the corrupt merger between state and corporate power that has ruined our economy, shattered the middle class, polluted our landscapes and waters, poisoned our children, and robbed us of our values and freedoms," he added. "Together we can restore America's democracy."

Comparison drawn between Biden and Carter

As the Daily Mail reported, Kennedy is the nephew of former President John F. Kennedy, who was assassinated in 1963 in Dallas, Texas, and the son of the former U.S. attorney general and late Sen. Robert F. Kennedy, who was assassinated in 1968 in California during his own run for the presidency.

The outlet further noted that he is not the first member of the Kennedy family to challenge an incumbent Democratic president, either, as another of his uncles, the late Sen. Ted Kennedy (D-MA), tried unsuccessfully to defeat then-President Jimmy Carter in the 1980 primary for the Democratic Party's nomination.

Coincidentally enough in terms of mirroring the current day, the 1980 Kennedy challenge against the sitting Democratic president came amid high inflation and a sluggish economy, an energy crisis, and disastrous foreign and domestic policies that resulted in low public approval numbers.

President Biden, of course, is also dealing with persistently high inflation and economic woes, a global energy crisis created in part by his own domestic policies, multiple foreign policy blunders, and consistently dismal job approval ratings.

Kennedy's anti-vaccine activism

The Associated Press reported that Robert F. Kennedy Jr. was well-known and highly regarded for quite some time as a best-selling author and attorney focused on environmentalism and protecting the climate and water from pollution.

Around 15 years ago, however, he became intensely focused on his opposition to vaccines and quite outspoken about the potential health risks they can pose to some individuals, and even established an anti-vaccine charitable organization known as Children's Health Defense.

That vocal opposition to vaccines only became more concerted during the coronavirus pandemic, and his charity's revenues more than doubled to around $6.8 million in 2020, as he loudly expressed his concerns with regard to the safety of the swiftly rolled-out vaccinations against the COVID-19 virus.

Kennedy instead urged people to consider alternative treatments for COVID infections like hydroxychloroquine and ivermectin and was exceptionally critical of Dr. Anthony Fauci, the longtime head of the National Institute for Allergy and Infectious Disease who became the face of the federal government's pandemic response.

Campaign announcement likely coming soon

Fox News reported that an unnamed adviser to Kennedy wouldn't confirm the formalized candidacy but did say that "the campaign will issue a statement tomorrow."

The outlet also noted that Kennedy, during a recent visit to deliver a speech at the New Hampshire Institute of Politics, said of his then-still hypothetical candidacy, "I’m thinking about it, and I’ve passed the biggest hurdle, which is my wife has green-lighted it."