Robert F Kennedy Jnr suspended his independent campaign for US president and endorsed Donald Trump on Friday in a late-stage shakeup of the presidential race that could give the former president a modest boost from Mr Kennedy’s supporters.

Mr Kennedy said his internal polls had shown that his presence in the race would hurt Mr Trump and help Democratic nominee Kamala Harris, though recent public polls do not provide a clear indication that he is having an outsize impact on support for either major-party candidate.

Mr Kennedy cited free speech, the war in Ukraine and a “war on our children” as among the reasons he would try to remove his name from the ballot in battleground US states.

Independent presidential candidate Robert F Kennedy Jr announces he is suspending his presidential campaign at a news conference in Phoenix, Arizona
Independent presidential candidate Robert F Kennedy Jr announces he is suspending his presidential campaign at a news conference in Phoenix, Arizona (Darryl Webb/AP)

“These are the principal causes that persuaded me to leave the Democratic Party and run as an independent, and now to throw my support to President Trump,” Mr Kennedy said.

However, he made clear that he was not formally ending his bid and said his supporters could continue to back him in the majority of states where they are unlikely to sway the outcome.

Mr Kennedy took steps to withdraw his candidacy in at least two states late this week, Arizona and Pennsylvania, but in the battlegrounds of Michigan, Nevada and Wisconsin, election officials said it is too late for him to take his name off the ballot even if he wants to do so.

Mr Kennedy said his actions followed conversations with Mr Trump over the past few weeks. He cast their alliance as “a unity party” – an arrangement that would “allow us to disagree publicly and privately and seriously”.

Hours after Mr Kennedy made his announcement in Phoenix, Mr Trump was to hold a rally in neighbouring Glendale.

Mr Trump’s campaign teased that he would be joined by “a special guest,” though neither campaign responded to messages about whether Mr Kennedy would be that guest.

A year ago, some would have thought it inconceivable that a member of arguably the most storied family in Democratic politics would work with Mr Trump to keep a Democrat out of the White House.

Even in recent months, Mr Kennedy has accused Mr Trump of betraying his followers, while Trump has criticised Mr Kennedy as “the most radical left candidate in the race”.

Republican presidential nominee former president Donald Trump talks with reporters at a campaign event in Las Vegas
Republican presidential nominee former president Donald Trump talks with reporters at a campaign event in Las Vegas (Julia Nikhinson/AP)

Five of Mr Kennedy’s family members issued a statement on Friday calling his support for Mr Trump “a sad ending to a sad story”.

“We want an America filled with hope and bound together by a shared vision of a brighter future, a future defined by individual freedom, economic promise and national pride,” read the statement, which his sister Kerry Kennedy posted on X, formerly Twitter.

“We believe in Harris and Walz. Our brother Bobby’s decision to endorse Trump today is a betrayal of the values that our father and our family hold most dear.”

Mr Kennedy, the son of the late US attorney general and senator Robert Kennedy and the nephew of president John F Kennedy, acknowledged his decision had caused tension with his immediate family. He is married to actress Cheryl Hines.

“This decision is agonising for me because of the difficulties it causes my wife and my children and my friends,” Mr Kennedy said. “But I have the certainty that this is what I’m meant to do. And that certainty gives me internal peace, even in storms.”

The Kennedy and Trump campaigns have ramped up their compliments of each other and engaged in behind-the-scenes discussions in recent weeks, according to those familiar with the efforts.

Both campaigns have spent months accusing Democrats of weaponizing the legal system for their own benefit. And both have hinted publicly that they could be open to joining forces, with the shared goal of limiting Ms Harris’ chances.

Mr Trump told CNN on Tuesday that he would “love” an endorsement from Mr Kennedy, whom he called a “brilliant guy”.

Election 2024 DNC Photo Gallery
Democratic presidential nominee Vice President Kamala Harris speaks during the Democratic National Convention in Chicago (Brynn Anderson/AP)

He also said he would “certainly” be open to Mr Kennedy playing a role in his administration if he dropped out and endorsed him.

Mr Kennedy’s running mate, Nicole Shanahan, also suggested on a podcast this week that his campaign might “walk away right now and join forces with Donald Trump”.

While she clarified that she is not personally in talks with Mr Trump, she entertained the idea that Mr Kennedy could join Mr Trump’s administration as secretary of the Department of Health and Human Services.

“I think that Bobby in a role like that would be excellent,” Ms Shanahan said. “I fully support it. I have high hopes.”

Earlier Friday, Ms Shanahan posted on X that she isn’t a Kamala Democrat or a Trump Republican.

“I’m an INDEPENDENT American who is endorsing ideas, not a person or a party,” she wrote. “I will continue working to give a voice to the voiceless and bring power back to the people.”

Mr Kennedy first entered the 2024 presidential race as a Democrat but left the party last fall to run as an independent.

He built an unusually strong base for a third-party bid, fuelled in part by anti-establishment voters and vaccine sceptics who have followed his anti-vaccine work since the Covid pandemic.

But he has since faced strained campaign finances and mounting legal challenges.

Recent polls put his support in the mid-single digits. And it is unclear if he would get even that in a general election, since third-party candidates frequently do not live up to their early poll numbers when voters actually cast their ballots.