ABC News August 23, 2024

From 'liberal lunatic' to 'respect': How Trump's stance on RFK Jr. has evolved

WATCH: RFK Jr. Suspending campaign, endorses Trump

Robert F. Kennedy Jr. announced on Friday that he is suspending his independent presidential bid and endorsing Republican candidate former President Donald -- but the two men haven't always gotten along, both hurling insults throughout their campaigns.

When Kennedy first signaled plans to jump into the 2024 race, Trump said he felt confident that Kennedy would take votes away from President Joe Biden, labeling him a far-left liberal.

"Kennedy is a Radical Left Democrat, and always will be!!! It's great for MAGA, but the Communists will make it very hard for him to get on the Ballot," Trump posted on his social media platform in March.

MORE: RFK Jr. says in new court filing he will endorse Donald Trump
Thomas Machowicz/Reuters
Independent presidential candidate Robert F. Kennedy Jr. makes an announcement on the future of his campaign, Aug. 23, 2024, in Phoenix.

Kennedy fired back in an April post on X, criticizing the former president and saying that Trump's rant against him "is a barely coherent barrage of wild and inaccurate claims" and challenged Trump to a debate.

At a Texas rally in May, Kennedy said a vote for Trump or Biden would result in getting "the same thing," while a vote for him will lead to "something altogether different. You're going to get healing."

As Kennedy ramped up his public attacks on Trump and earned spot on ballots, Trump changed his tune, urging his supporters not to "waste" time voting for him.

Jose Luis Magana/AP
Robert F. Kennedy Jr. speaks during the Libertarian National Convention at the Washington Hilton in Washington, May 24, 2024.

"Don't waste any Republican or Conservative votes on Junior.' He's one of the most Liberal Lunatics ever to run for office," Trump posted on his social media platform in late May.

While speaking at the National Rifle Association Convention on May 18 in Dallas, Trump compared Kennedy to an annoying fly that was buzzing around him.

"He's radical left; RFK Jr. is radical left. Reminds me of this fly that's driving me crazy up here. This fly is brutal. I don't like flies," he said.

Trump did acknowledge that Kennedy may take votes away from him.

Evan Vucci/AP
Republican presidential nominee former President Donald Trump speaks on crime and safety during a campaign event at the Livingston County Sheriff's Office, Aug. 20, 2024, in Howell, Mich.

"They say he hurts Biden, I think, I'm not sure that that's true. I think he probably hurts both," he said in an interview with Real America's Voice on April 22. "But he might hurt Biden a little bit more, you don't know."

Trump has also called Kennedy the "dumbest member" of the Kennedy family -- a political dynasty.

MORE: RFK Jr. says he has 'no plans to endorse' Harris after he recently tried to set up meeting with her

Trump has recently softened his stance on Kennedy, saying in an interview with CNN on Tuesday, "I like him a lot, I respect him a lot." He indicated that Kennedy would likely have a role in a Trump administration, too.

At a campaign event in Arizona on Thursday, Trump called Kennedy "very smart" and even said it would be a "great honor" to earn an endorsement from Kennedy.

"Well, I don't want to get too much into it, because you're telling me something I don't know, other than I've always been friendly with him. If he were going to endorse me, I would consider it a great honor," Trump said.

However, he did later say that an endorsement does not necessarily mean Kennedy is getting a position in his administration.

"No, it doesn't mean administration, but certainly having his endorsement, because things that he agrees on, I also agree on," he said on NBC News.