Stephen Colbert wonders if a white supremacist will pick Trump's VP 'and he'll just retweet it'

Now that both parties appear to have presidential nominees, Stephen Colbert wondered whom those candidates would choose as their running mates.

Colbert said a lot of Democrats wanted Hillary Clinton to choose Elizabeth Warren, who has already been attacking the presumptive Republican nominee.

"She said, 'Donald Trump is a loud, nasty, thin-skinned fraud,'" Colbert said. "Listen, that is just wrong -- there's no way that stuff covering his face is skin."

Trump says he's narrowed his list of candidates down to four or five -- although, Colbert said, "if it's a woman, she's definitely a 10."

The real estate developer and reality TV star said he would announce his running mate choice at the convention, but some of his advisors are reportedly worried he'll announce the pick without warning on Twitter.

"Or (maybe) a white supremacist will post it and he'll just retweet it," Colbert said.

Bernie Sanders remains in the Democratic presidential race despite losing in California's primary, and the Vermont senator met Thursday at the White House with President Barack Obama.

"Which was fitting, since they're both beloved political figures who are just a few months away from not being president," Colbert said.

Sanders said he's willing to back his rival to defeat Trump, and Obama endorsed Clinton as possibly the most qualified presidential candidate in history.

"Suck it, third-term FDR," Colbert joked. "I've got to be honest, those are words I never thought I'd say in my entire life."

Trump fired back at the endorsement on Twitter, saying "Crooked Hillary" was basically "four more years of Obama," and Clinton responded by urging the GOP candidate to delete his account.

"If he needs help deleting computer records, she knows a guy," Colbert said.

Watch the entire segment posted online by The Late Show With Stephen Colbert: