In South Carolina, the group bought ad time in the weeks preceding the Republican contest and ran a series of ads urging supporters to vote for Herman Cain, who had recently dropped out of the race amid allegations of sexual impropriety. One of the ads, narrated by actor John Lithgow, mocked Republican frontrunner Mitt Romney as a "serial killer" of corporations.

But operations seem to have dried up for the super-PAC, which spent just $765 in June on a minimal consulting and storage fee.

Still, Colbert's group could come back with a vengeance once the presidential campaign intensifies again this fall. The group still holds more than three-quarters of a million dollars in cash-on-hand.