Woody Harrelson has entered the political discourse with an apparent endorsement for Democratic Presidential primary challenger and notorious anti-vaxxer Robert F. Kennedy Jr.

And social media users were none too pleased about it.

RFK Jr. is the son of former Senator and Attorney General Robert F. Kennedy, and the nephew of Democratic President John F. Kennedy and Democratic Senator Ted Kennedy.

The longtime anti-vaxxer has come under fire in recent years–including by members of his own family–for emerging as a leading opponent the COVID-19 vaccine and for spreading vaccine misinformation at the onset of the pandemic.

He recently claimed without evidence at a New York dinner event that COVID-19 was a genetically-engineered weapon that targeted Caucasians and Black people and spared Ashkenazi Jews and Chinese people.

Even in the wake of this controversy, Harrelson posed for a photo with RFK Jr.'s wife, actress Cheryl Hines, and wore a blue baseball cap with the words:

"Kennedy 2024"

Hines, who has appeared in Curb Your Enthusiasm, posted the photo and wrote in the caption:

"Great seeing you Woody."

Reactions to his hat choice supporting the Democratic presidential challenger to President Joe Biden in 2024 were mixed.

Some users expressed their approval of Harrelson's endorsement of the conspiracy theorist.

@_cherylhines and @robertfkennedyjr/Instagram

@_cherylhines and @robertfkennedyjr/Instagram

@_cherylhines and @robertfkennedyjr/Instagram

While others felt let down by their favorite actor.

@_cherylhines and @robertfkennedyjr/Instagram

@_cherylhines and @robertfkennedyjr/Instagram

@_cherylhines and @robertfkennedyjr/Instagram

@_cherylhines and @robertfkennedyjr/Instagram

@_cherylhines and @robertfkennedyjr/Instagram

A similar sentiment was shared widely on X, formerly Twitter, with this viral post:

Harrelson responded to the backlash by telling TODAY through a representative:

"Bobby is a personal friend."

"I don’t endorse candidates from either party because I’m an anarchist."

RFK Jr. also addressed Harrelson's cap controversy during his first campaign stop at the Iowa State Fair on Saturday.

He told Fox News Digital that he reached out to Harrelson and suggested the actor was unaware of causing a stir with the photo of him and Hines because he is "kind of off the grid."

"I’ve texted with him. You know, he’s very hard to get a hold of."

"He’s been a friend for many, many years. He’s very close to me and Cheryl."

"One thing is he doesn’t like cell phones. It’s conceivable that he does not know about all of the controversy."

"He doesn’t watch TV. He doesn’t have his cell phone and he’s kind of off the grid."

I guess Kennedy has the off-the-grid no phone constituency locked up, then.