Kerry Kennedy Leads ‘Heart-Wrenching’ Campaign Against Her Brother’s White House Bid

When members of the Kennedy family joined President Biden in Philadelphia to endorse his re-election — and denounce the presidential candidacy of the best-known Kennedy of this generation, Robert F. Kennedy Jr. — one person stepped forward to make the family’s case: his younger sister Kerry.

“Nearly every single grandchild of Joe and Rose Kennedy supports Joe Biden,” Ms. Kennedy said as her siblings, and Mr. Biden, flanked her onstage. “That’s right: The Kennedy family endorses Joe Biden for president.”

That was not the first time that Ms. Kennedy, the seventh child of Robert and Ethel Kennedy, had been the face of the family’s pushback against her brother. As Mr. Kennedy has emerged as a skeptic of Covid-19 vaccines and a purveyor of conspiratorial theories on the assassination of his father, it has fallen to Ms. Kennedy to distance her familyfrom the brother she has long held close and to guard the legacy of a proud and private family as it fades from the political stage.

To a large extent, Ms. Kennedy’s siblings say, her outsize role is an outgrowth of the affection she has displayed toward her brother since they were children playing on the grounds of the family estate in Hickory Hill, Va. — and the disappointment she feels now. It is political as well: She argues that her brother’s insurgent campaign threatens the re-election of Mr. Biden and is aware that her family could shoulder some of the blame should Donald J. Trump return to the White House next year.

“I love Bobby,” she said in an interview. “It’s heart-wrenching to be in this position.”

But Kerry Kennedy’s decision to help lead an inevitably awkward effort against a family member also reflects her concern about the legacy of Robert F. Kennedy Human Rights, the organization founded upon her father’s death in 1968 that she has led for 15 years.

As its president, she has championed causes that reflected her father’s work: international human rights, fighting against disparities in health care and advocating for immigrants. In some cases, the positions that have been embraced by her brother, particularly his opposition to Covid vaccination, have run directly counter to the mission of the organization.