Watch Jimmy Fallon as Bruce Springsteen: 'Robert Mueller's Comin' to Town'

Stephen Colbert also sang Trump indictment Christmas carol for "holiday collusion season"

On Monday, late-night TV hosts hoped that Robert Mueller's investigation would lead to charges against President Trump.

Jimmy Fallon and Stephen Colbert found the holiday spirit in the latest results of Robert Mueller's investigation into collusion between Russia and President Trump's administration. On Friday, former National Security Advisor Michael Flynn pleaded guilty to lying about conversations he had with the Russian ambassador and agreed to cooperate with Mueller's inquiry. 

On The Tonight Show, Fallon resurrected his spot-on Bruce Springsteen impression – donning Aviator sunglasses, a red bandana, sleeveless denim and one earring – and adapted the words of Springsteen's rendition of "Santa Claus Is Comin' To Town." "You better watch out, you better not cry, you better not lie to the FBI," Fallon sang. 

"He sees your Russian meetings, he's read all your emails ... He knows that you tried to collude, it isn't fake news for goodness' sake." Fallon ended the performance with a cheerful ad-lib: "All your asses are going to jail! Merry Christmas!"

Colbert took a different tack on The Late Show, assembling an eight-person choir that reworked the carol "The 12 Days of Christmas" in honor of "holiday collusion season": "On the first day of Christmas Bob Mueller gave to me/ A Michael Flynn guilty plea." 

The ensemble made it to through four verses before their resolve broke down. "On the fifth day of Christmas, Bob Mueller gave to me/ Please speed this up/ I won't last 12 days, cut to the trial," the choir sang. They finished with a cry for help: "We can't take it anymore."