PHILADELPHIA — Robert F. Kennedy Jr. announced Monday that he will run for president as an independent, abandoning his quest to challenge President Joe Biden for the Democratic Party nomination.

Kennedy, the son and namesake of an assassinated former U.S. senator and presidential candidate, revealed his new course of action at an early afternoon rally for supporters on Philadelphia’s Independence Mall, a location he chose for its proximity to where the country was founded.

“People stop me everywhere … and they remind me that this country is ready for a history-making change. They are ready to reclaim their freedom ― their independence!” he declared to a cheering crowd. “And that’s why I’m here today ― I’m here to declare myself an independent candidate” for president.

Kennedy went on to outline how his ideologically heterodox campaign, focused on healing the partisan divide, would “declare independence” from the corrupting influence of corporations, the “mercenary” media, the “cynical elites,” and of course, the two-party system.

As a Democratic candidate, Kennedy, an environmental-attorney-turned-vaccine-skeptic and conspiracy theorist, upset expectations with the significant support he garnered in some polls, though that support has waned over time.

But the Democratic National Committee has refused to schedule debates between Biden and other Democratic hopefuls.

Kennedy also lamented new party rules making South Carolina the first primary state and penalizing candidates who campaign in the unsanctioned New Hampshire primary, saying this had stacked the race against him. (The party has laid those rules out openly, but Kennedy has made additional, baseless claims about the DNC’s alleged plans to interfere with his bid.)

“So how are we going to win against the established Washington interests?” Kennedy said in a video teasing his Philadelphia rally. “It’s not through playing the game by the corrupt rules that the corrupt powers and vested interests have rigged to keep us all in their thrall.”

Kennedy’s decision follows a similar step by left-wing academic and activist Cornel West, who announced Thursday that he would run as an independent rather than vie for the Green Party’s presidential nomination. He told CNN that seeking the Green Party nomination required too much internal party campaigning and that it was easier to obtain a place on the ballot in all 50 states as an independent.

Marianne Williamson, a self-help author and spiritual guru, remains in the race for the Democratic presidential nomination. She has thus far failed to break through in polling.

Unlike Williamson, however, Kennedy and West could both siphon votes from Biden in a general election.

Kennedy has espoused conventionally liberal views on climate change, racial justice and the welfare state while also opposing the United States’ continued arming of Ukraine, the administration of a suite of vaccines whose risks he believes have been concealed by Big Pharma and the government, and the closures of schools and other public places for public health reasons during the COVID-19 pandemic.

Kennedy has also expressed more conservative views than Biden on the question of shutting down unauthorized entries at the U.S. border, gun rights, and parents’ role in decisions about their children’s gender transitions.

As a Democratic candidate, Kennedy received much more coverage — and favorable treatment — from right-wing media outlets than from mainstream or liberal outfits. It is unclear whether that will continue now that he is no longer challenging Biden in the Democratic primary.

The Republican National Committee wasted no time blasting Kennedy as a “typical elitist liberal” as Kennedy made the announcement Monday afternoon.

“Make no mistake ― a Democrat in Independent’s clothing is still a Democrat,” RNC Chairwoman Ronna McDaniel said in a statement. “RFK Jr. cannot hide from his record of endorsing Hillary, supporting the Green New Deal, fighting against the Keystone Pipeline, and praising AOC’s tax hikes ― he is your typical elitist liberal and voters won’t be fooled.”

In a hypothetical general election matchup with both Biden and former President Donald Trump, who is the polling leader in the GOP primary, Kennedy would receive 14% of the vote, pulling support from both major party candidates, according to a Reuters/Ipsos poll that came out Thursday.

This is a developing story. Please check back for updates.