Colbert, who is not on the ballot, says he has believed Cain's message for "several days now."
He appeared with Cain at a rally Friday at the College of Charleston and told the more than 3,000 people that a vote for the former candidate would send a strong message that the people want Colbert.
Cain demurred and told the crowd to vote for whomever they want.
Colbert called it the "Rock Me Like a Herman Cain South Cain-olina Primary Rally."
