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, mkatz@phillynews.com, or @mattkatz00 on Twitter.