Reid's comments come after The Washington Post published audio of the businessman making explicit comments about trying to have sex with women, which were caught on a hot mic in 2005. Trump issued a half-apology, saying the comments were private "locker-room banter" and "I apologize if anyone was offended."

But they've stopped short of dropping their support for the presidential nominee roughly a month before the November election.

Reid, however, questioned if Republicans aren't willing to cut ties with Trump — who he called a "sociopath" and a "racist" — “what will it take for Republicans to walk away from Trump?"

"This is a moment of truth for Republicans. It is time for every Republican elected official in this county to revoke their endorsements of Donald Trump and state that they will not vote for their party's nominee, who has been caught on tape bragging about routinely sexually assaulting women. There is no way to defend the indefensible," he said.

The outgoing Senate Democratic leader is the latest Democrat to seize on Trump's comments Friday, arguing GOP senators have to walk away from their nominee.

Republicans are defending 24 Senate seats in November, and have walked a fine line with Trump: Distancing themselves from his controversies while refusing to cut ties with him and his base of voters that they will need to win reelection.

Democrats need to net five seats — or four if they also retain the White House — to win back the Senate.