By Nandita Bose, Trevor Hunnicutt and Stephanie Kelly
PHILADELPHIA (Reuters) -Fifteen members of the storied Kennedy political family endorsed U.S. President Joe Biden at a Philadelphia campaign event on Thursday, with some joining him onstage, in a rebuke of Robert F. Kennedy Jr's independent bid for office.
Biden, a Democrat, faces Republican Donald Trump in a November re-match of the 2020 election. But members of both parties have bristled over the possibility that the candidacy of Kennedy, a prominent anti-vaccine activist, or another third-party bid could spoil either of their chances.
Kennedy, son of the slain U.S. senator and presidential candidate Robert F. Kennedy, made his name as an environmental lawyer, before becoming known as an anti-vaccine advocate with an eclectic mix of political views. He is backed by 15% of registered voters, versus 39% for Biden and 38% for Trump, according to a recent Reuters/Ipsos poll.
Many in Robert F. Kennedy Jr's elite family - prominent Democrats since the 19th century - have broken with him over his views.
"I can only imagine how Donald Trump's outrageous lies and behavior would have horrified my father, Robert F. Kennedy," Robert F. Kennedy Jr's younger sister Kerry Kennedy said at the Biden campaign event, calling Trump the most "anti-democratic president ever." "Daddy stood for equal justice, human rights, and freedom from want and fear. Just as President Biden does today."
"A vote for Joe Biden is a vote for our democracy and our decency," Kerry Kennedy added. She did not mention her candidate brother in her speech.
She added that she and her family were at the event because they feel obligated to do all they can to support Joe Biden's campaign.
Kennedy family members are then expected to join local volunteers in door-knocking and phone-banking on Biden's behalf, campaign aides said.
Robert F. Kennedy Jr said on social media platform X that he had heard some of his family was endorsing Biden.
"I am pleased they are politically active - it's a family tradition," he wrote. "We are divided in our opinions but united in our love for each other."
The event on Thursday was part of Biden's third day this week in Pennsylvania, a critical swing state for his re-election bid. Biden needs strong turnout from Philadelphia's Black community to win the state, and the Kennedys became icons because of their advocacy for civil rights.
TRUMP, BIDEN GROUPS HONE IN
For its part, the Democratic National Committee has emphasized donations supporting Robert F. Kennedy Jr's candidacy from billionaire Timothy Mellon, a major MAGA Inc donor, pushing the concept that Kennedy Jr is a "stalking horse" for Trump.
That differs from the approach of those supporting Trump, including the Make America Great Again Inc super PAC, which has aimed to paint Robert F. Kennedy Jr as a "leftist radical."
The efforts by the two parties underscore concerns they both have that Kennedy could take votes away from their candidate.
Biden, only the second Catholic president after John F. Kennedy, has long spoken of how he was inspired by the family's legacy, and added on Thursday that the family members' endorsement was an "incredible honor."
In his 2007 book "Promises to Keep," Biden describes himself as moved to get into public service by the Kennedy brothers and the activist Martin Luther King Jr., "swept up in their eloquence, their conviction, the sheer size of their improbable dreams." A bust of President Kennedy sits in the Oval Office.
When Biden was later elected to Congress, fellow Senator Ted Kennedy would become one of his closest friends. Ted, John and Robert Sr. were brothers.