It’s not every day that a family clash plays out on social media in front of hundreds of thousands—but that’s exactly what’s happening between John F. Kennedy’s only grandson, Jack Schlossberg, and his cousin, Robert F. Kennedy Jr. And this isn’t just a polite political disagreement.
It’s gotten deeply personal, bizarrely provocative, and at times downright uncomfortable.
Jack Schlossberg, the only son of U.S. Ambassador Caroline Kennedy, has once again gone after his cousin—this time in a head-turning video posted to Instagram.
Sitting behind a desk with the American flag beside him, Schlossberg issued a strange challenge to RFK Jr., calling him out over his controversial views on autism and vaccines.
“Me and You, One-on-One”: Schlossberg’s Strange Challenge
In the video, Schlossberg mockingly challenged RFK Jr. to a bizarre showdown.
“Me and you, one-on-one, locked in a room. We hash this out. Nobody comes out until one of us has autism,” he said, clearly mocking his cousin’s widely criticized stance on what’s behind the rising autism rates in the U.S.
His comments were aimed at RFK Jr.’s recent press conference, where the presidential hopeful blamed environmental toxins—and not genetics or improved diagnoses—for what he called a “tsunami” of autism in children.
Kennedy’s remarks have sparked outrage among medical professionals and families, who say his theories are unproven and dangerous.
What RFK Jr. Really Said About Autism
At the heart of this family feud is RFK Jr.’s ongoing campaign against what he sees as environmental causes of autism.
He’s dismissed the widely accepted science that says autism is largely genetic and pointed the finger instead at toxins, medications, and even ultrasound technology.
Citing a rise in autism diagnoses from one in 56 children in 2016 to one in 31 in 2022, Kennedy has insisted this surge isn’t just due to better diagnosis.
“Doctors weren’t stupid back then,” he argued. “They weren’t missing all these cases.”
He’s promised to launch new studies within weeks to pinpoint the environmental triggers he believes are to blame.
Scientists Aren’t Buying It
But many experts strongly disagree. Researchers behind the CDC’s report on rising autism rates pointed to more access to early screening and changing diagnostic standards—not some sudden wave of environmental threats.
They also mentioned variations in insurance coverage as a possible reason behind the spike in numbers.
Even some autism researchers who agree that more studies are needed have called out RFK Jr.’s claims.
Dr. Richard Frye, a pediatric neurologist, said Kennedy is right to question the effects of common drugs like acetaminophen—but slammed his comments about ultrasounds and toxins as “misguided” and based on little to no evidence.
A Long-Running Kennedy Clash
This isn’t the first time Schlossberg has taken a swing at his cousin.
Ever since RFK Jr. launched his ill-fated presidential campaign in 2023, Jack has made it clear he doesn’t think much of him.
He’s previously accused his cousin of exploiting the Kennedy name for fame and conspiracy theories, even calling him out during RFK Jr.’s Senate confirmation hearing.
Jack’s mother, Caroline Kennedy, hasn’t held back either—describing RFK Jr. as a “predator” and “dangerously misinformed” about vaccines.
Her comments made headlines when she urged senators to block his nomination.
From Political Jabs to Personal Attacks
But lately, Jack’s attacks have gone from sharp critiques to borderline shocking.
Earlier this year, he went on Instagram again to mock RFK Jr.’s voice disorder—a condition called spasmodic dysphonia.
He also bizarrely accused high-profile lawyer Alan Dershowitz of murder, a claim that quickly drew threats of legal action and calls for a psychiatric evaluation.
Schlossberg briefly vanished from social media after that storm of backlash, but returned within a month.
His comeback post was another jaw-dropping video in which he taunted RFK Jr.’s wife, actress Cheryl Hines, blaming her for a child’s measles death and mispronouncing her name on purpose.
The Kennedy Family Tries to Distance Itself
According to insiders, the rest of the Kennedy clan is quietly cringing.
While they’ve long distanced themselves from RFK Jr.’s views, they’re also reportedly fed up with Jack’s over-the-top social media behavior.
One family source told DailyMail.com that they don’t feel responsible for Jack’s actions—insisting he’s “more Schlossberg than Kennedy.”
“Jack’s got his father’s personality, not the Kennedy charisma,” said the insider, adding that his erratic posts are more about drama than political discourse.
What’s Next for the Kennedy Cousins?
At this point, it seems unlikely that either cousin will be making peace any time soon.
Jack Schlossberg shows no signs of backing down from his online crusade, and RFK Jr. continues to make headlines with controversial statements and ambitious claims.
For a family that has long represented political legacy and public service, this very public feud is drawing a very different kind of attention—one that’s as dramatic as it is uncomfortable.