"I want you to vote for Herman Cain, because Herman Cain is me!" Colbert said to a roar from thousands of mostly college-age voices.
Because there's no write-in option for South Carolina's Republican presidential primary Saturday, and because the ballots were finalized before Cain dropped out of the contest, Colbert asked supporters to make a vote for Cain a vote for him. He's even aired commercials funded by a super-PAC he founded - the same kind of super-PAC that dominates political advertising in this race.
The rally culminated Colbert's nine-month effort, televised nightly, to raise money for his super-PAC. The point was to educate the public about how this new kind of political fund-raising works while exposing the loophole-laden law that lets big money sneak into the process.
A lifelong South Carolinian, J.G. Walker, 55, who vowed to vote Cain/Colbert on Saturday, said: "One of my Republican friends said, 'You're making a mockery of the system.' I said, 'Exactly!' "
The rally, taped to be telecast on Colbert's show Monday, came a day before the second anniversary of the Citizens United Supreme Court decision barring the government from limiting political spending by corporations and unions.
That decision spurred the growth of super-PACs, some of which are run by friends or associates of candidates they support, though coordination is forbidden. Some commercials that super-PACs underwrite have contained negative or even false attacks on rivals.
To get around the no-coordination rule, Colbert got on-air advice from his attorney (a former Federal Election Commission chairman), handed control of his super-PAC to his friend and Comedy Central colleague Jon Stewart, and changed its name to the Definitely Not Coordinating With Stephen Colbert Super-PAC. Its motto - Making a Better Tomorrow, Tomorrow - remained unchanged.
Colbert has raised money from viewers through the super-PAC's website, and through such methods as catching balls of rolled-up cash thrown at him on the street. In keeping with super-PAC rules, he has not revealed how much he has raised, but he has funded several absurd commercials. One calls Mitt Romney a serial killer.
It was all legal, Colbert repeatedly assured viewers. That was his point.
"You can thank the Supreme Court by going into that voting booth and voting for Herman Cain!" he declared Friday on the campus' Cistern Yard, where candidate Barack Obama rallied in 2008. "Because, sadly, it is still illegal to vote with just pure cash."
After a marching band warmed up the crowd, Colbert sang "This Little Light of Mine" with a gospel choir. Listeners, some leaning from windows in Randolph Hall, screamed affection.
The media, he said, thought the rally was a joke. "If this is a joke, then they are saying our whole campaign-finance system is a joke!"
Colbert said he had declined another candidate's offer to join him in an open marriage - "though I am flattered Newt Gingrich asked me."
Several high school and college students said they skipped class to attend. None would say whether their chanting "USA!" was ironic.
"Politics is a joke, and he's making light of it," said College of Charleston sociology major Keri Carter, 24, who told of voting for John McCain in 2008. "We can't get the change we want, so we're out here having fun."
Cain/Colbert has a chance to be a wild card in Saturday's primary because non-Republicans are allowed to vote.
Paula Feldman, 63, an Obama voter in 2008 who already voted for Cain/Colbert via absentee ballot, drove two hours from Columbia, S.C., where she's an English professor. "I think Stephen Colbert is the most interesting, intelligent, and politically-savvy person on the ballot," she said.
But he's not on the ballot, someone said.
"He's Herman Cain!" she replied. "And I think it would be totally cool if Stephen Colbert-slash-Herman Cain got more votes than any of the actual candidates."
It was unclear whether Cain got the gag. In his speech, the former pizza executive plugged his new organization, Cain Solutions. He made pro-tea party remarks, criticized Obama - coolly received by the crowd - and said, "Stay inspired!"
The words weren't met with silence, exactly. But it was clear: If his listeners were inspired by 2012 politics, they wouldn't be at a non-rally rally in the first place.
Contact staff writer Matt Katz at 609-217-8355, email@example.com, or @mattkatz00 on Twitter.