Bryan Alexander

USA TODAY

LOS ANGELES — Robert De Niro lashed out at Donald J. Trump, calling the Republican presidential candidate "insane" from the podium of the Hollywood Film Awards on Sunday night.

De Niro compared Trump to off-kilter movie characters in front of a supportive crowd at the Beverly Hilton Hotel.

The Trump comparisons included the "totally insane" General Jack D. Ripper, who pushed the world to "nuclear Armageddon” in Stanley Kubrick's Dr. Strangelove. De Niro said the Ripper character was not a stretch from the "totally insane" Trump.

"I know we’re here to celebrate movies in Hollywood. But it’s two days before a frightening election and the shadow of politics is hanging over us whether we like it or not. And it’s hard for me to think about anything else," said De Niro.

Stars receive Hollywood Film Awards honors (and then mock them)

"So let me lay it out right here. We have the opportunity to prevent comedy from turning into a tragedy," De Niro added. He advocated voting for Hillary Clinton on Tuesday, bringing a cheer from the crowd.

De Niro, who received the Hollywood Comedy Award for his role in The Comedian, has gone after Trump before. In October, the Oscar-winner took Trump to task, calling him "a punk, a dog, pig, a con (and) a (BS) artist" in a video that went viral.

"He's a mutt who doesn't do his homework, doesn't care, thinks he's gaming society, doesn't pay his taxes," De Niro said in the video.

In August, De Niro called Trump "totally nuts" during a film festival discussion.

Leonardo DiCaprio also got political from the HFA podium, accepting the Hollywood Documentary Award for Before the Flood, a film he made with director Fisher Stevens about global warming.

DiCaprio pointed out that during the widely-viewed presidential and vice presidential debates, not one question was asked about global warming.

"That is completely unacceptable," said DiCaprio, who called global warming "an urgent threat to life on Earth."

"There’s no more time for arguing or clouding the facts or for spreading campaigns of misinformation. All of us need to act," said DiCaprio.

DiCaprio urged: "Lets all use our power as citizens and do the right thing. Please vote this Tuesday."

Host James Corden went political during his opening, pointing out that Star Wars and Ghostbusters were "brought back with a female lead."

"I pray to God they reboot the Clinton presidency with a female lead," said Corden.