That trend meant Trump went from leading Biden by 2 percentage points in a head-to-head survey to trailing him by 2 points when the race is expanded to five named candidates, including Kennedy. The survey’s margin of error is plus or minus 3.1 percentage points.

Republican voters view Kennedy much more favorably than Democrats. The poll found that 40% of self-identified Republicans viewed Kennedy favorably, while 15% held negative views of the independent candidate. For Democrats, just 16% had positive views of Kennedy, while 53% expressed a negative view of him.

That’s in part the result of conservative media and Trump allies heaping praise on Kennedy when he was initially running in the Democratic primary against Biden, as well as prior to this election cycle as Kennedy, a prominent vaccine skeptic, railed against the medical establishment and so-called social media “censorship.”

A Republican who worked on a door-knocking effort in an early state for a Trump primary opponent told NBC News that Kennedy often came up as the second choice among people who said they were backing Trump.

A changing posture

Trump himself has offered kind words for Kennedy in the past. During a June 2023 interview on the Howie Carr Show, Trump described Kennedy as “a common sense guy.” Right-wing allies like Steve Bannon, Alex Jones and Roger Stone openly pined for Trump to pick Kennedy as his running mate. 

The vibe is different now.

The pro-Trump PAC MAGA Inc. this month launched a “Radical F—ing Kennedy” website dedicated to promoting the candidate’s left-wing positions. Kennedy, meanwhile, has criticized Trump from the right, hitting him for taking advice from Dr. Anthony Fauci during the pandemic and for running up the deficit. He said another Trump term “would be bad for the country.”

“President Trump calls me an ultra-left radical,” Kennedy posted on X in response to the MAGA Inc. website. “I’m soooo liberal that his emissaries asked me to be his VP. I respectfully declined the offer.”  (Trump’s campaign has denied that Kennedy was ever approached about being the former president’s running mate.)

“I am against President Trump, and President Biden can’t win,” Kennedy’s post continued. “Judging by his new website, it looks like President Trump knows who actually can beat him.”

On the whole, there have been public surveys showing both major party candidates suffering more as a result of Kennedy’s campaign. The dynamic also may change depending on which state is being surveyed — and which states feature Kennedy on the ballot in November, a battle that is still in progress.

“Nobody has conducted more polls than I have on Kennedy and his place in the race — and continuously I have seen him draw equally from Biden and Trump,” said Jeremy Zogby, a managing partner at John Zogby Strategies who has polled for Kennedy’s campaign. “Sometimes a point or two towards one side in a poll, and vice versa in another poll. The fact remains Kennedy has crossover appeal among those disaffected within both parties,” like the “double haters” who dislike both Biden and Trump.

Democrats have long worried that Kennedy’s association with his famous father and uncles will win over some liberals who are fond of the family. Plus, Kennedy for years gained acclaim as an environmental activist and an anti-corporate crusader, two causes that have him finding common ground with Democratic voters.

Last week, Biden held an event with Kennedy family members who touted the president and warned of the danger their relative’s campaign posed. And on Monday, the Democratic National Committee announced it was launching billboards in Arizona depicting Kennedy as a pro-Trump spoiler candidate.

A strategist working on the Democrats’ anti-third party effort said the data shows Kennedy is clearly taking a slice from both major party candidates, as well as a portion of voters who wouldn’t be open to voting for either Trump or Biden.

“I think the data’s moved a little bit over the last month-plus,” this person said. “But it’s all on the margins, it’s tough to tell whether this is RFK appealing more to Trump voters, or some Trump voters just looking for an off-ramp, or both. Ditto on the Biden end — is this just reflecting the fact that Biden’s ticked up a few points?”

One Trump ally said the presumptive GOP nominee should hold off on hitting Kennedy for now, arguing there will be time later this fall to go after him as “too liberal for America” if these polling trends continue.

“The second you start attacking him or even addressing him, you start giving credibility to and you start firming up those votes,” this person said, “At the moment, he’s irrelevant. As you get close and votes start hardening in terms of who people are voting for and when and why and how, then you’ve got to start making moves.”

In a statement, Trump’s campaign railed against Kennedy’s environmental positions and described him as “no independent,” while also hitting Democrats for challenging his efforts to get on the ballot.

“RFK Jr. is an AOC lover and opposes really any human advancement, preferring that we all live in caves by candlelight, except of course supports charging stations for your $150,000 electric car that can only drive a few miles before dying just like his presidential campaign,” said Steven Cheung, Trump’s communications director.

Tony Lyons, a co-founder of the pro-Kennedy super PAC American Values 2024 and the president of Skyhorse Publishing, said there will be a “pendulum swinging back and forth” throughout the campaign that shows Kennedy at times being better for Trump and at other times boosting Biden’s candidacy. 

Lyons said Kennedy will soon be promoting a 30-minute infomercial posted online that aims to hit back on the attacks he’s facing from his rivals.

“The fascinating part of it is that Trump says he’s ultra left-wing,” Lyons said. “And Biden says that he’s ultra right-wing.”