"They should both put on 'Make America Great Again' hats and stand behind Trump at his next press conference. Be a mini-(Chris) Christie, I guess," Reid said, referencing the New Jersey governor's endorsement
The Nevada Democrat was speaking at the liberal Center for American Progress Action Fund in Washington, delivering a speech entirely aimed at blasting the real estate mogul.
"The Republican establishment acts bewildered. But they shouldn't. As much as they may try to distance themselves
from Trump now, Republican leaders are responsible for his rise," he said.
He attacked his Senate colleagues for trying to distance themselves from Trump's rise, saying they bear the responsibility.
"When Trump calls immigrants rapists and murderers
, he's just doing what he's learned from generations of conservatives," Reid said. "The Republican Party has become the party of Trump."
Reid said Republican leaders including McConnell and Ryan have "tried to have it both ways" on Trump, giving him a verbal "slap on the wrist" when he says something objectionable but still affirming they'll back him if he's the ultimate nominee.
"This is precisely the kind of moral cowardice that gave rise to Donald Trump," Reid said, calling on McConnell and Ryan to unequivocally repudiate Trump.
Ryan and McConnell have both spoken out against comments and policies from Trump, including when he called for a temporary ban on all foreign Muslims
entering the U.S. and violence at his rallies.
But they have also said they will support the Republican nominee and have not backed down when asked if that would include Trump.
Reid said it's time to go farther.
"There is no gray area here. It is time for Sen. McConnell and Speaker Ryan to find the backbone to say: 'Enough,' " Reid said.
The speech was largely an airing of grievances for Reid against the GOP. He railed on the majority party for obstructionism in the Senate, seeking to delegitimize President Barack Obama, denying climate change and opposing Obama's Supreme Court nominee.
Reid, who said last year he will not run again after his term ends,
also predicted a difficult fall for moderate Republican senators running for reelection on the same ticket as Trump.
"I don't know how anyone, some of these people who are running for reelection, Rob Portman, Roy Blunt, I just don't know how these people can run and say, 'Why I'm supporting this person for president.' And they can't run away from it," Reid said.
He said he didn't predict much success for them with Texas Sen. Ted Cruz
at the top of the ticket, either, but he did have some faint praise for the GOP senator who's been a thorn in Democrats' and Republicans' sides alike in the Senate.
"I have to say this about Cruz: He at least has some principles, I don't like what he stands for, but he stands for something," Reid said. "I'm not as turned off by Cruz because he stands for things. Trump stands for nothing."