CNN — The Kennedys have been through a lot. They don’t want to go through this.

No name has appeared on more ballots or lawn signs. Even across branches of the family that have grown distant and divided since the first generation rose to power in the 1960s, they celebrate each cousin’s achievement – whether that’s a seat in the House or a new children’s book or an expansion of the Special Olympics.

But Robert F. Kennedy Jr.’s campaign challenging President Joe Biden for the Democratic nomination – set to be announced Wednesday in Boston – is too much for a family that defined the modern Democratic Party. They’re frustrated, sad and completely opposed.

They say they love him. They use words like “heartbroken” and “tragic.”

It’s the vaccine skepticism, which includes a book about “The Real Anthony Fauci” and saying Anne Frank was better off than Americans under supposed vaccine mandates because she could at least hide from the Nazis. It’s insisting that Sirhan Sirhan didn’t actually shoot Kennedy’s father, and breaking with many in the family years ago to argue for the assassin’s parole. Now, it’s going up against a president whose administration is stocked with Kennedys in prominent positions and who has decades of personal and emotional connections to multiple members of the family.

They see the very namesake of one of the original brothers trying to leverage the most storied family legacy in Democratic politics, for what many of them have been saying privately is a vanity run that is doomed. And that they want to be doomed.

“They’re angry to be put in this position – because they always want to support the family, but they’re being put in a position that makes that impossible,” said one person who has spoken to several members of a family generally so guarded that even longtime aides often feel like they barely understand the dynamics themselves.

“Which brother?” Chris Kennedy, a former gubernatorial candidate in Illinois, joked when asked by CNN about his thoughts on his brother’s campaign.

“This is a difficult situation for me. I love my older brother Bobby. He has extraordinary charisma and is a very gifted speaker,” Rory Kennedy, the filmmaker and youngest child of Robert F. Kennedy, told CNN. “I admire his past work as an environmentalist – because of him, we can swim in the Hudson. But due to a wide range of Bobby’s positions, I’m supporting President Biden.”

“I prefer not to talk,” texted Kathleen Kennedy Townsend, the former Maryland lieutenant governor who’s now an adviser on retirement at the Labor Department, when asked about the frustration within the family about her brother’s run.

Kennedy Townsend’s assessment is clear, though: She co-authored a 2019 article with her brother former Rep. Joe Kennedy II and her late daughter bemoaning that Robert F. Kennedy Jr. “helped to spread dangerous misinformation over social media and is complicit in sowing distrust of the science behind vaccines.” Among her many pro-Biden tweets, meanwhile, is one a few weeks ago with a picture of the president walking in Kyiv with Ukrainian President Volodymyr Zelensky calling them, with a JFK nod, “Two Profiles in Courage.”

Robert F. Kennedy Jr. acknowledged his family’s “close personal friendship” with Biden in a statement to CNN in which called out Biden’s handling of the war in Ukraine as of one of “the bad decisions” he disagrees with: “It has been my difficult choice to put my principles ahead of my personal affections for the President which remain undiminished. Some members of my family agree with me and others do not. I bear them no ill will. Families can disagree and still love each other. We hold that possibility for the entire country too.”

But he’s leaning hard into his family connections from the start: He’s launching the campaign in Boston – a city where he never lived but that is closely associated with his family – in a hotel where his uncle, the late Sen. Ted Kennedy, often appeared. He devoted three of the six sentences in the news release about his candidacy to the fact that he “hails from one of the most famous families in American political history” and the winking, semi-accurate statement that his father “mounted a major campaign in a tumultuous primary that dislodged the incumbent Democratic President Lyndon Johnson.” Promoting the announcement, he tweeted a photo of himself wearing a T-shirt with the image of a 1960s “KENNEDY FOR PRESIDENT” campaign button.

Kerry Kennedy, another sister and the president of the Robert F. Kennedy Human Rights Foundation, drew a larger distinction between the family and the campaign.

“I love my brother Bobby,” she said, “but I do not share or endorse his opinions on many issues, including the COVID pandemic, vaccinations, and the role of social media platforms in policing false information. It is also important to note that Bobby’s views are not reflected in or influence the mission or work of our organization.”

Her cousin Bobby Shriver, the former mayor of Santa Monica, California, and a co-founder of the (RED) corporate anti-AIDS campaign, subtweeted the news Kennedy filed paperwork with the Federal Election Commission earlier this month: “A good day to say I was thrilled to be an early support[er] of Joe Biden in 2015? Excited to work hard again!”

Patrick Kennedy, the former Rhode Island congressman who’s the son of Ted Kennedy, the younger cousin of Robert F. Kennedy Jr. and an advocate for mental health and addiction issues, told CNN his feelings on the campaign are clear: “I support President Biden.”

Among other reasons, he said, that’s because Biden has done “more than any other president” to enforce a bill that prohibits insurance companies from discriminating against people with mental illnesses or addictions and because of his broader support for efforts to reform the mental health and substance use disorder system.

For many Kennedys, Robert F. Kennedy Jr. taps into a deeper existential fear for the family. The Americans who revered the original brothers are well into retirement age and starting to die. Even the memories of the next generations’ tabloid dramas and curse-like tragedies have begun to fade. They worry that the real effect of this presidential campaign may not be taking many delegates from Biden but making people think that what he stands for is what the family’s all about.

“President Kennedy signed the original Community Mental Health Act of ’63. Attorney General Robert Kennedy created the Office of Juvenile Justice and Delinquency Prevention in order to intervene early in young people’s lives, and my father was primary Senate sponsor of parity,” said Patrick Kennedy. “These issues, and the incredible legacy that they all had on civil rights – from JFK being the first president to address the issue on national TV to RFK standing with Dr. King to my father’s seminal work on the Voting Rights Act – and immigration reform, are at the heart of my family’s legacy.”

Decades of deep Kennedy connections for Biden

Biden has been quoting one of the less famous lines from John F. Kennedy’s 1961 moonshot speech since his first doomed run for president in 1987. He usually says it as, “We refuse to postpone,” though the actual quote Kennedy quote was, “We are unwilling to postpone.” He has a clipped section of the original prompter script, given to him by Caroline Kennedy, framed and hanging in his private study in the White House. Bobby Kennedy, Biden has often said, was one of two heroes – along with Martin Luther King Jr. – for him as a young man entering politics. He keeps busts of both on his desk in the Oval Office.

But the connection for Biden is about more than political inspiration. After the car crash that killed Biden’s first wife and baby daughter a few weeks after he was first elected to the Senate in 1972, Ted Kennedy was a consoler and confidant, another young senator who had worked his way through grief and mourning in office.

That meant many long sessions in Kennedy’s office in the Hart Senate Office Building. Less known, though arguably more meaningful to the future president, were multiple train trips Kennedy made to Delaware to see Biden and his family in those months.

Biden has said that the late senator made him feel like he was his little brother. At the opening of the Edward M. Kennedy Institute for the US Senate in 2015, then-Vice President Biden called him “my tutor and my guide.”

On Air Force One last week en route to Belfast with former Rep. Joe Kennedy III (RFK’s grandson, RFK Jr.’s nephew and now Biden’s special envoy to Northern Ireland), Biden called Ethel Kennedy (RFK’s widow and his soon-to-be primary challenger’s mother) to wish her a happy 95th birthday.

“He said he went into politics because of Robert Kennedy, Uncle Ted was a great help when his family died in the car crash and Jack Kennedy was the first Irish president going to Ireland and now he’s the second, and he hopes he can fill Jack’s shoes,” Kerry Kennedy recounted on Instagram with an old picture of Biden and Ethel Kennedy together, framed by a heart. “Mum replied, ‘We love you Joe and Joe!’”

A Biden-Kennedy administration

At almost the same moment Biden was on that call, second gentleman Doug Emhoff was at the Kennedy Presidential Library in Boston, across the bay from the planned presidential announcement, talking about combating hate and antisemitism in a speech introduced by John F. Kennedy’s granddaughter Tatiana Schlossberg.

The event, planned long before Robert F. Kennedy Jr. filed his presidential paperwork, was just the latest example of how intertwined the Kennedys are with the Biden administration. In addition to Kathleen Kennedy Townsend at the Labor Department and Joe Kennedy in Northern Ireland, Caroline Kennedy – John F. Kennedy’s daughter and Schlossberg’s mother – is the ambassador to Australia, and Vicki Kennedy – Ted Kennedy’s widow – is the ambassador to Austria.

Biden last appeared at the Kennedy Presidential Library last September, to talk about the expansion of his own “Cancer Moonshot” effort. He mentioned the solace he had gotten from a letter Vicki Kennedy sent him after Beau Biden’s death, which referred to how family patriarch Joseph Kennedy had once written to a friend after his own had son died about how after the life of someone close ends, “you wonder what you’re going to do with the rest of yours.”

Biden ran for president in 2020 partly because he felt he was running the campaign he had once envisioned for his late son.

Asked for Vicki Kennedy’s thoughts about her nephew’s campaign – or how the family connection might affect her diplomatic work for the man he’s challenging – a spokesperson from the US Embassy in Austria said only that the “ambassador does not make any statements concerning the family, including any political activities of family members.”

Then again, the first thing in her personal Twitter account bio after being a proud mother, grandmother and dog lover is that she “believe[s] in vaccinations.”

An aide to Caroline Kennedy in the US Embassy in Australia did not return a request for comment.

Worries about the personal toll for a sibling, cousin, uncle

Multiple Kennedys and friends of Kennedys talk wistfully about the Bobby they say they used to know, with stories about him saving birds with broken wings and giving them to siblings as gifts, or his environmental work in New York with the group Riverkeeper, which many assumed would lead to a potentially front-running campaign for New York attorney general in 2006 that never materialized.

That’s been overtaken in their minds by a sense that he’s lost his way. In addition to their other worries about the campaign, several Kennedys and friends told CNN that out of love for him, they are concerned that a campaign will lead to digging up past pain like his drug problems in the 1980s and a troubled marriage to his second wife, who died in 2012.

So the best they can hope for, several said, is that this campaign ends quickly and quietly.

If his campaign starts to make waves, though, and if Biden launches his own campaign as expected, Robert F. Kennedy Jr. may end up being what unites the disparate family, one of them joked – for an event where many Kennedys stand together to endorse Biden.