Some conservatives on Twitter were calling for the Secret Service to investigate the motivations behind a tweet from Hollywood filmmaker Joss Whedon Tuesday.

Here's what Whedon tweeted

Whedon tweeted that he wanted the president to die because he was emboldening "monsters."

"Donald trump is killing this country," he tweeted. "Some of it quickly, some slowly, but he spoils and destroys everything he touches. He emboldens monsters, wielding guns, governmental power, or just smug doublespeak. Or Russia. My hate and sadness are exhausting. Die, Don. Just quietly die."

Whedon, who is lauded by fans for creating "Buffy the Vampire Slayer" and "Firefly," has a long history of controversial liberal commentary against Trump and other Republicans.

In 2012, Whedon created a video mocking presidential candidate Mitt Romney by representing him as a zombie. In 2014, he opined that men shouldn't be able to have any opinion about women's reproductive rights, meaning abortion, at all.

“Isn’t that like rabbis electing a pope?” he said.

After Trump's surprising 2016 victory, Whedon said that he must not be allowed to have a term in office.

What was the reaction?

Many on Twitter didn't appreciate the over-the-top rhetoric from Whedon:

"This complete maniac is a disgrace to himself, his family, his community, the country and anyone who knows him," said former Secret Service agent Dan Bongino.