Democrats have kicked into high gear to combat what they see as the threat that Robert F. Kennedy Jr.’s independent presidential bid could pose to President Joe Biden’s reelection. The Democratic National Committee has a team dedicated to countering Kennedy and other third-party candidates, and big donors are investing in a super PAC to do the same.

But the nature of Kennedy’s appeal is not fully understood, and if he manages to get on the ballot in key states, he could pull as many votes, or more, away from former President Donald Trump as from Biden.

“I’m trying to discern what it is,” said Chuck Coughlin, a political strategist and ex-Republican in Arizona whose consulting firm does frequent polling in the swing state. “Does [Kennedy] attract Republican voters who are not Trumpers, who don’t want to vote for Biden? I’ve got to think there’s something there.”

Asked for comment on his potential appeal to Trump voters, the Kennedy campaign sent a lengthy response rejecting the premise of the story.

“This push comes in part from a genuine inability of the establishment parties to understand a candidate who does not fit into conventional political categories. In fact, we are neither right nor left, neither liberal nor conservative,” Kennedy campaign spokesperson Stefanie Spear said in a statement. “The key policy positions that Mr. Kennedy and Ms. Shanahan share defy those categories. Is ending the forever wars liberal, or conservative? How about freeing agencies from corporate capture? Ending the chronic disease epidemic? Protecting free speech?

“The DNC and GOP try to pigeonhole our candidates as liberals or conservatives, which perpetuates the divisiveness that has paralyzed our political system,” she continued. “Both are screaming, ‘He’s one of THEM!’ Our ticket represents the broad majority who have unsubscribed from the right-left paradigm.”

Kennedy, an environmental attorney and scion of the famous Democratic dynasty, is polling at roughly 12% nationally against Biden and Trump, though it’s not entirely clear who his supporters are. Some election-watchers think he poses an equal threat to Biden and Trump, while others believe his candidacy is nominally worse for Biden. Kennedy’s campaign finance reports, however, suggest his base may be people who haven’t been moved in recent elections to vote for either major-party candidate.

Despite the attention given to RFK and his campaign, third-party candidates historically flame out in presidential elections, generally struggling to get more than 1% of the popular vote. The most successful third-party candidate in modern U.S. history was Texas billionaire Ross Perot, who managed to win 19% of the vote in 1992.

Perot’s fortune helped him obtain ballot access in 50 states. But it is not yet clear how Kennedy will fare against the thicket of arcane rules the two major parties erect to prevent outsiders from getting on the ballot. Kennedy’s campaign website says that he has collected enough signatures to get on the ballot in Hawaii, Nevada, New Hampshire and Utah. And his allied super PAC says it has enough signatures in Arizona and Georgia as well.

Assuming that Kennedy is eligible for ballots across the country — which would be thanks in no small part to the financial and legal help he is due to get from his wealthy new running mate, attorney Nicole Shanahan — his potential appeal to Trump voters is obvious.

He is perhaps the most prominent vaccine skeptic in the country at a time when negative polarization has made anti-vaccine sentiment far more welcome on the right. He rails against the so-called deep state, a favorite talking point of Trump’s. And he shares the populist right’s opposition to additional U.S. arming of Ukraine.

As a candidate, Kennedy has also expressed more conservative views on border enforcement, protecting gun rights, and ending transgender women’s participation in competitive women’s sports.

“There are issues that the right agrees with RFK on. There are issues that the left agrees with RFK on,” said Matt Mackowiack, a Texas Republican consultant, who cited Kennedy’s positions on vaccines and foreign policy as stances that might appeal to conservative voters. “The question is: Is he going to be able to micro-target those voters with the most effective message on the issues that might be able to pull those voters away from a major-party candidate?”

Ellen Carmichael, a GOP strategist who has worked on presidential campaigns, thinks Kennedy has a shot at wooing the so-called “double haters,” the significant portion of voters (up to a fifth of the electorate) who seriously dislike both Biden and Trump.

Kennedy’s vaccine skepticism in particular could appeal to voters on the right who are still angry with Trump for COVID-19 lockdowns early in the pandemic, she said.

“The fundamentals of the race are that an overwhelming majority dislike both candidates, but of that swing population, just a lot think [Trump’s] a bad guy,” Carmichael said. “I think that dynamic helps Kennedy at Trump’s expense, because there are a lot of people who are unhappy with the Trump administration’s approach to COVID.”

To Zac McCrary, a Democratic pollster, Kennedy’s appeal for voters on the right is more about the “anti-establishment, burn-it-all-down vibe.”

“At the end of the day, Kennedy can leverage some of the ‘weirdo factor’ ― and in 2024, there are more Trump weirdos than Biden weirdos,” McCrary said.

A Democratic strategist working on the presidential race noted that Kennedy’s appeal seemed to center on two distinct groups in internal polling: older voters, many of them women, who still had positive associations with the Kennedy name dating back to the senior Robert Kennedy and President John F. Kennedy; and younger voters, mostly men, who shared the candidate’s conspiratorial worldview. Drawing each of those groups of voters away from Kennedy would require divergent strategies, the strategist said.

There’s not a great deal of polling that models which voters Kennedy draws from. In March, Biden led Trump 39% to 38% nationally, with Kennedy receiving 15%, according to a Reuters/Ipsos poll. The poll found that if voters only had a head-to-head choice between Biden and Trump, Biden would lead Trump 50% to 48%, suggesting that Kennedy pulled only slightly more votes from Biden than from Trump.

“It’s a long way to Election Day, but that doesn’t mean we’re going to wait to define him,” said Matt Corridoni, a senior adviser in the DNC’s anti-third party unit. “That work starts now.”

There are signs that official GOP organs no longer view Kennedy as an asset. When Kennedy initially announced he was mounting a Democratic primary challenge against Biden last April, Republicans were his biggest cheerleaders. He was a regular guest on conservative media, and Trump called him a “very smart person.”

All that changed in October, when Kennedy abandoned his bid for the Democratic nomination in favor of an independent run. Suddenly, Republicans were eager to highlight the areas in which Kennedy is genuinely closer to the median Democratic politician: his environmentalism and his support for the traditional, liberal welfare state.

“Make no mistake ― a Democrat in Independent’s clothing is still a Democrat,” then-Republican National Committee Chair Ronna McDaniel said in a statement at the time. “RFK Jr. cannot hide from his record of endorsing Hillary [Clinton], supporting the Green New Deal, fighting against the Keystone Pipeline, and praising [Rep. Alexandria Ocasio-Cortez’s] tax hikes ― he is your typical elitist liberal and voters won’t be fooled.”

Trump’s campaign sounded a similar note following Kennedy’s announcement of Shanahan, a Silicon Valley lawyer and philanthropist with similarly unorthodox views, as his running mate on Tuesday.

“RFK Jr. is a radical leftist ― an environmental whack job who loves EV mandates, [and] wants to end gasoline powered engines,” Trump’s communications director, Steven Cheung, said in a statement Thursday. “He’s no Independent. RFK Jr. is an AOC lover and opposes really any human advancement, preferring that we all live in caves by candlelight, except of course [he] supports charging stations for your $150,000 electric car that can only drive a few miles before dying just like his presidential campaign.”

It will likely become easier to depict Kennedy as a fire-breathing leftist with his selection of Shanahan as a running mate, argued Mackowiack, who is also chair of the Travis County, Texas, Republican Party.

In her acceptance speech, Shanahan, a longtime Democratic donor, spoke about the importance of the social welfare state to her during her humble upbringing, and about ending the school-to-prison pipeline. Shanahan even donated to Los Angeles’ controversial, progressive district attorney, George Gascón, The Washington Free Beacon, a conservative outlet, reported on Tuesday.

Given the opportunity to pick a conservative or centrist running mate, Kennedy “went with a liberal ― I don’t think you can really debate that,” which suggests he is trying to appeal more to Democrats and Democratic-leaning independents than to Republicans and Republican leaners, Mackowiack said.

Perhaps based on its own conclusion that Kennedy poses only a limited threat to Trump — or perhaps simply because of its severe shortage of funds — the RNC has yet to mount a dedicated initiative to stamp out Kennedy. And GOP donors have likewise refused to launch a super PAC operation against him.

In fact, some Republican megadonors apparently still see Kennedy’s campaign as a benefit to Trump. Timothy Mellon, a billionaire entrepreneur and member of the old-money Mellon clan, is a massive donor both to Republican causes and to Kennedy’s presidential run. A longstanding contributor to Republican candidates, Mellon has contributed $16.5 million to the pro-Trump super PAC Make America Great Again Inc., as well as over $20 million to the pro-Kennedy super PAC American Values 2024.

“Being propped up by Trump’s largest donor tells voters all they need to know about RFK’s candidacy: He’s a spoiler for Trump,” Corridoni said.

Kevin Robillard contributed reporting.