(The Hill) — Donald Trump Jr. dubbed presidential candidate Robert F. Kennedy Jr. a “Democrat plant” after the candidate left the Democratic primary to pursue a presidential bid as an independent, potentially hurting former President Trump’s election chances.

“It legitimately always felt like it was a Democrat plant to hurt the Trump thing,” Trump Jr. said to Trump campaign volunteers in Iowa on Thursday, NBC News reported. “He wouldn’t be there if the Democrats didn’t want him.”

The Democratic establishment essentially ignored Kennedy’s longshot primary bid against President Biden. Now, early polls show that Kennedy may actually pull more voters from Trump than Biden in a three-man race, turning a former primary opponent into a boon for the president.

Kennedy centered his campaign on a rejection of the two-party system, distrust in government and skepticism of COVID-19, including the COVID vaccine.

Those positions could appeal to voters who otherwise would vote for Trump, political analysts have argued.

Even other GOP candidates have predicted that Kennedy could hurt Trump.

“You have another wrinkle now with RFK Jr. as a third party,” Gov. Ron DeSantis (R-Fla.) said at a stop in New Hampshire this month. “RFK Jr. will be a vessel for anti-lockdown and anti-Fauci voters if Trump is the nominee.”

“He would hurt Trump,” DeSantis predicted.

But Trump Jr. disagrees, pointing to Kennedy’s more liberal stances on immigration and gun control, among other issues.

“He should be much more of a threat to Joe Biden than to us,” Trump Jr. said Thursday. “Once you actually look at his voting record, you’re like, no, he’s just a liberal that is anti-vax … being anti-vax, I don’t think that’s enough.”