The Late Show With Stephen Colbert opened Thursday night with the host making an emotional request to Republicans to speak up against President Donald Trump's unfounded claims of election fraud.

Earlier in the evening, Trump held a White House press conference in which he made multiple baseless claims of widespread voter fraud, and claimed to have won states in which votes were still being counted, including razor-thin races in Georgia and Pennsylvania.

“The president came out into the White House briefing room and lied for 15 minutes,” Colbert said. “Just nonsensical stuff about illegal vote dumps and corrupt election officials and secret Democratic counting cabals and, I don’t know, long-form birth certificates probably. It’s all the same.”

Colbert then pointed out how the president's reaction was predictable after his pre-election rants against early and mail-in voting. Even in 2016, Trump said he would accept the results of the election only if he won.

“So we all knew this was coming…” Colbert said before stopping for several seconds to compose himself. “…what I didn’t know is that it would hurt so much. I didn’t expect this to break my heart. For him to cast a dark shadow on our most sacred right from the briefing room in the White House...Our house, not his. That is devastating.”

Trump’s press conference drew sharp criticism from many on both sides, and Colbert called on Republicans to put the president in check.

“For all the predictable behavior of the last few days, and the last four years,” Colbert said, “right now something unpredictable needs to happen. Republicans have to speak up. All of them.”

Very few Republicans have criticized Trump’s claims, and Colbert called on the rest to make the choice between the American people and what he sees as fascism.

“You only survived this up ’til now because a lot of voters didn’t want to believe everything that was obvious to so many of us: That Donald Trump is a fascist,” Colbert said. “And when it comes to democracy versus fascism, I’m sorry, there are not fine people on both sides. So you need to choose, Donald Trump or the American people.”

“Americans are gonna count something else staring right now,” Colbert said. “They are gonna count who was willing to speak up against Donald Trump trying to kill democracy. And they’ll count who will stay silent in the face of this desperate attack on the bedrock institution of this truly great nation.”

Stepen Colbert
“The Late Show” host Stephen Colbert at the Showtime Golden Globe Nominees Celebration at Sunset Tower in Los Angeles on Jan. 6, 2018. Getty Images/ Matt Winkelmeyer

Chris Christie, a frequent supporter of Trump, was one of the few GOP representatives to criticize the president.

"We heard nothing today about any evidence," the former New Jersey Gov. said on ABC. "This kind of thing, all it does is inflame without informing. And we cannot permit inflammation without information."