Did Trump share his real opinion on childhood vaccines with anti-vaccine crusader Robert F. Kennedy Jr.?

On Sunday, a day after surviving an assassination attempt and the day before formally winning the Republican presidential nomination, former President Donald Trump put in a call to one of the other candidates in the race, and it wasn’t President Joe Biden. Instead, Trump called Robert F. Kennedy, Jr., an independent presidential candidate who has for months consistently registered some 10 percent support in polls. Kennedy Jr. is also America’s most famous opponent of vaccines, a subject Trump chose to talk about in a video recording of the phone call that Kennedy Jr.’s son subsequently posted on the internet. ​

According to NBC reporter Brandy Zadrozny, Robert Kennedy III posted and then deleted the video of his father talking to Trump on X, the social media platform formerly known as Twitter. “I’m a firm believer that these conversations should be had in public. Here’s Trump giving his real opinion about vaccinating kids—this was the day after the assassination attempt,” Kennedy III wrote.

Kennedy Jr. later apologized to Trump, saying he was “mortified” by the posting of the video.

The video shows Kennedy Jr.—who has a long history of vaccine skepticism—taking the call in a room that contains an American flag. Although the conversation is not always audible in the video, Trump clearly expressed his skepticism about childhood vaccinations. “When you feed a baby, Bobby, a vaccination that is like 38 different vaccines, and it looks like it’s meant for a horse not a 10-pound or 20-pound baby. It looks like you should be giving a horse this [inaudible word],” Trump told Kennedy. “And did you ever see the size of this? You know it’s this massive—and then you see the baby all of a sudden begin to change radically. I’ve seen it too many times. And then you hear that it doesn’t have an impact, right?”

Kennedy Jr.’s candidacy has been a thorn in the side for both Trump and Biden.

Kennedy Jr. is the nephew of John F. Kennedy, the charismatic Democratic president who in 1963 was killed by an assassin’s bullet in Dallas. Kennedy Jr.’s father, Robert F. Kennedy, attracted widespread support during a 1968 run for the presidency before being assassinated in a hotel kitchen after a Los Angles campaign event. Other members of the Kennedy family have been so worried that Kennedy Jr.’s association with the famous political dynasty might draw from Biden’s support that over a dozen members of the family gathered to endorse the president in April.

Yet Kennedy Jr. has also given Republicans reason for concern, with some polling showing he garners more support from Republican-leaning voters than Democratic-leaning ones. Even though they run counter to scientific evidence, Kennedy Jr.’s criticisms of vaccines closely align with the attitudes of the many Republicans who turned against vaccine and masking mandates implemented at the height of the COVID-19 pandemic. Florida Gov. Ron DeSantis, at one point a top contender for the Republican presidential nomination, said he might put Kennedy Jr. in a position at the Centers for Disease Control and Prevention (CDC) or the Food and Drug Administration (FDA), both of which have a role in vaccine policy. As president-elect before his first term officially began, Trump reportedly flirted with creating a position in which Kennedy Jr. would review vaccine policy. Kennedy Jr. claimed Trump at one point offered to put him on the ticket as a candidate for vice president. On Monday, Trump reportedly met with Kennedy to discuss Kennedy dropping his presidential bid and endorsing Trump.

As he campaigns for president as an independent, Kennedy Jr. is on leave from his anti-vaccine nonprofit, Children’s Health Defense. The group posts content that links vaccines to health problems, including autism, even though such links are unsupported by scientific evidence. The theory connecting vaccine use to autism in children has its origins in an article by discredited UK doctor Andrew Wakefield in The Lancet, a prestigious scientific journal. In 2010, Britain’s General Medical Council, a regulatory body, found that Wakefield had been paid by lawyers working on vaccine injury claims and said that the study involved children who had been carefully selected. The Lancet  retracted the article after the findings.

A variety of studies have found no connection between vaccines and autism. Even so, Kennedy Jr.’s views have persisted even as he runs for president. Last July, Kennedy Jr. told a podcast that “[t]here’s no vaccine that is safe and effective,” according to the Associated Press.

As he runs for president for a third time, Trump has worked to court vaccine-skeptical audiences. His message to them could be tough to sell. Trump, after all, oversaw the Operation Warp Speed project that rapidly produced and distributed COVID-19 vaccines. He took the vaccine, even though it was much maligned by many Republicans, and encouraged Americans to get it themselves. That history represents a political problem for Trump amid growing resistance to vaccines—not just to COVID-19 vaccines, but even to the routine childhood vaccines currently required by every state for every child attending public school.

Still, Trump has tried recently to distance himself from his prior support for vaccination, saying on the campaign trail that if he is elected this year, he would not allow mandates requiring COVID vaccine or masks at school. At the same time, he has claimed that he is not opposed to routine childhood vaccinations.

But the conversation between Trump and Kennedy Jr. calls into question Trump’s level of support for any vaccine. In the leaked video, the former president used language about vaccines that he’d used in a 2007 newspaper interview. Autism, Trump told the South Florida Sun-Sentinel then, “wasn’t really a factor,” when he was young but had subsequently become a crisis. “My theory is the shots,” Trump reportedly said. “We’re giving these massive injections at one time, and I really think it does something to the children.”