When Robert F. Kennedy Jr. announced his presidential campaign on April 19 in Boston, he highlighted his family’s political pedigree and his history of championing “numerous environmental causes,” saying he was running to “end the corrupt merger of state and corporate power.” Notably absent was any direct acknowledgement of the decades-long crusade that has made the 69-year-old the most famous face of the anti-vaccine movement in the country.
It was a stark contrast to the speeches he was giving last year. In January 2022, Kennedy rallied thousands of people from the steps of the Lincoln Memorial in Washington at a massive demonstration opposing vaccine mandates in which he shared discredited conspiracies about COVID-19 and compared U.S. public health officials’ actions to Nazi Germany.
As the pandemic fades from public view, the anti-vax movement finds itself in a state of flux. Kennedy’s decision to not even use the word “vaccine” in his announcement speech likely reflects his desire to gain traction in the Democratic primary among voters looking for an alternative to President Joe Biden. It’s a different story on the other side of the aisle, where some candidates appear to be actively courting a right-wing contingent made up of anti-vaxxers and vaccine skeptics, opponents of public health mandates, and conspiracy theorists that grew during the pandemic. The extent to which presidential candidates embrace the sentiment could signal whether the movement, and the larger anti-science conspiracies and anti-government views associated with it, has staying power in the American electorate.
Before 2020, the idea of anti-vaxxers having any kind of foothold in national politics was widely viewed as unthinkable. Yet now, a significant number of vaccine skeptics have “made this part of their identity, and engaging with them is actually going to harden their opposition,” says Dr. Tom Frieden, who served as the head of the Centers for Disease Control and Prevention from 2009 to 2017.
After years of engaging in anti-vaccine activism, Kennedy further built his following during the pandemic by capitalizing on many Americans’ distrust of public health officials, their fears of the virus, and widespread misinformation. He became one of the “Disinformation Dozen,” a group of twelve individuals identified by the the Centers for Countering Digital Hate as responsible for 65% of the anti-vaccine content on Facebook and Twitter. Last year, Facebook and Instagram removed the pages of his nonprofit, the Children’s Health Defense, for spreading medical disinformation. But to a growing audience of hundreds of thousands of supporters and online fans he was a hero, speaking out against dangerous schemes by government officials and pharmaceutical companies. Despite being a Democrat, he remains popular on right-wing anti-vax channels, where his candidacy was greeted with “Trump/RFK 2024!” stickers.
While Kennedy did not directly mention vaccines in his announcement, it was clear that was not necessary for his most enthusiastic supporters. “This is the candidate for vaccine truth that promises to dismantle the vaccine deep state!” one popular right-wing anti-vaccine Telegram channel told its 81,000 followers on April 16, encouraging them to attend his announcement in Boston. “RFK may not be perfect but we know he’d take a wrecking ball to the pharmaceutical industry and vaccines,” one poster said on a popular pro-Trump forum. “Even Trump may not do that.”
Five days after launching his campaign, Kennedy alleged on Twitter that Fox News had let go of Tucker Carlson because the right-wing host had claimed “that the TV networks pushed a deadly and ineffective vaccine to please their Pharma advertisers…Fox just demonstrated the terrifying power of Big Pharma.”
But Kennedy is not the only presidential candidate employing anti-vaccine rhetoric. The pandemic and resistance to the vaccine mandates that followed provided a surge of momentum to the movement, and spurred a partisan split that turned support of vaccines into a political litmus test. While vaccine skepticism has been limited to longshots like Kennedy on the left—President Joe Biden is widely expected to coast to the Democratic nomination—more prominent contenders on the right appear to be courting it.
“I think Robert Kennedy Jr. is in a class by himself, because a huge portion of what he works on is opposition to vaccination,” says Joshua Sharfstein, a public health professor at Johns Hopkins. “I don’t think he’s credible within his own family, let alone you know, as a national speaker on the topic … More concerning is the Florida governor.”
Florida Governor Ron DeSantis, who has fallen in polls recently but is still expected to challenge former President Donald Trump for the 2024 GOP nomination, has raised questions about the safety of vaccines in Florida. In December, DeSantis asked the Florida Supreme Court to empanel a grand jury to investigate “wrongdoing” tied to COVID-19 vaccines. “I think people want the truth that I think people want accountability,” DeSantis said at the time. “You need to have a thorough investigation into what’s happened with the shots.”
Read More: How the Anti-Vax Movement Is Taking Over the Right
The embrace of vaccine skepticism, and often anti-vaccine conspiracies, by many on the right turned the public health campaign into a partisan issue. A Washington Post-ABC poll conducted in June 2021 found that 47% of Republicans said they weren’t likely to get vaccinated against COVID-19, compared to 6% of Democrats. Unvaccinated adults are three times more likely to lean Republican than Democrat, according to a November 2021 analysis by the Kaiser Family Foundation.
“According to the data, there’s a pretty tight correlation between partisan beliefs about vaccines and death rates,” Frieden says. “Politicians respond to what their potential voters think and some of the people who will be voting in primaries have very strong beliefs about vaccines. … So that’s concerning.”
The politicization of COVID-19 vaccines led to an often bizarre spectacle, as Republican lawmakers became reluctant to publicly disclose their own vaccination status. In 2021, nearly half of House Republicans declined to say whether they had been vaccinated when asked by CNN. In New York City, a GOP city council member refused to disclose her vaccination status even though failing to do so barred her from entering the chamber.
DeSantis has staffed his administration with prominent vaccine skeptics. In 2021, in the midst of a nationwide public health effort to vaccinate Americans against COVID-19, he appointed vocal vaccine critic Joseph Ladapo as Florida’s Surgeon General. Since then, Ladapo has become a hero in online anti-vaccine communities, who follow his guidance over the advice of U.S. public health agencies.
Last year, guidance released by Ladapo warned against vaccinating men between the ages of 18 to 39, claiming there was a 84% increase in cardiac-related deaths related to the COVID shot. He also recommended against vaccinating healthy children, which contradicts U.S. public health guidance. This led to CDC and FDA leaders sending a letter to Ladapo last month. “It is the job of public health officials around the country to protect the lives of the populations they serve, particularly the vulnerable,” the federal letter said. “Fueling vaccine hesitancy undermines this effort.”
Trump, on the other hand, has a more complicated history with vaccine disinformation. In 2017, Kennedy said Trump had asked him to lead a vaccine safety commission in his administration. But in the wake of the pandemic, Trump vacillated between taking credit for the rollout of COVID-19 vaccines under his administration and seemingly recognizing that anti-vaccine sentiment has embedded itself among the MAGA faithful. After initially denouncing politicians who refused to disclose their vaccination status as “gutless,” the former President seemed to go quiet on the matter. But many in his orbit were still happy to engage: his son Eric spoke at a conference of anti-vaccine activists in Nashville last fall, and some of his most prominent supporters, including former Fox News host Tucker Carlson and strategist Steve Bannon, raised questions about the safety and efficacy of vaccines.
Should either DeSantis or Trump emerge from the Republican primary by stoking anti-vax fervor, they may regret it when it comes time for the general election, when they will have to appeal to the broader electorate.
“The vast majority of Americans understand the value of vaccines, and the importance of sufficient vaccination levels so that infectious diseases can’t threaten us all,” Sharfstein says.
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Write to Vera Bergengruen at vera.bergengruen@time.com and Mini Racker at mini.racker@time.com