About 11 p.m. EST, Stewart became possibly the first comedian to announce the presidential election result on live national television.
Sensing the end was imminent, the broadcast delayed its signoff for a moment, as offstage producers gave the closing cue while hovering over TV monitors showing CNN - and when they said the election had been called, the comedians effectively became newsmen.
Interrupting a Colbert writhing in mock disappointment at John McCain's loss, a clearly moved Stewart announced: "I would just like to say, if I may ... that at 11 o'clock at night, Eastern Standard Time, the president of the United States is Barack Obama."
It was a straight line on a broadcast full of parody.
Sitting at The Daily Show desk - expanded for the two anchors - Stewart and Colbert mocked over-the-top election coverage with fake reports from campaign headquarters and real updates on polling numbers.
"We don't normally do this live. We are a fake news show," Stewart told the crowd beforehand, putting emphasis on "fake."
But The Daily Show for years now has been regarded as a legitimate news source. Stewart's take on the news has been influential enough to draw visits from both McCain and Obama.
"The Colbert Report" host infused himself into the race by briefly - and comically - running in the South Carolina primary.
The two comedians - Stewart himself, Colbert in his right-wing pundit persona - reacted to the night's news like a Democrat and Republican, respectively. Most of the gags went to Colbert.
Repeatedly, Stewart called the night a historic one, only to have Colbert each time correct that it was "AN historic" evening.
A desperate Colbert attempted distraction with a cockatoo, scoffed at blue states like Vermont and pleaded that McCain's win in South Carolina was "this year's bonus state" - tripling its electoral tally.
Daily Show correspondents pitched in, too, including a video interviewing voters prodding for evidence of the so-called Bradley Effect - whether white people lie to pollsters about their willingness to vote for black candidates.
The phenomenon was first noted in 1982 when Tom Bradley, the black mayor of Los Angeles, endured a stunning defeat in the California governor's race after exit polls indicated he was the winner.
But comedy eventually subsided to the magnitude of the election results. After the broadcast - held in front of a raucous and partisan crowd - the cast exchanged hugs and Colbert and Stewart both went to the audience to embrace their wives.
In a brief interview after the broadcast backstage, Colbert was still rattled.
"I've never had this feeling before, which is: Things went well on Election Night," said Colbert, whose political views are not his character's. "I'm a little stunned. I don't know what to do with my happiness. I'm still afraid someone's going to take it away."
In the nearly two-year long presidential campaign, comedy was the unqualified winner, mirroring the candidates and the media every step of the way to great popularity. Like NBC's
"Saturday Night Live," "The Daily Show" and "The Colbert Report" each enjoyed record ratings and increased relevance.
The exit of the Bush administration, some have argued, will dwindle comedic fodder. But Tuesday night's show ended with Stewart rallying his correspondents and Colbert that their jobs would continue.
"There was a world out there before this election and there's still a world out there," Stewart said.
Afterward, Colbert, too, said the show would go on.
"It's like saying nighttime news will go out of business tomorrow," said a grinning Colbert. "Do you think that's gonna happen?"
