Last month, Elizabeth Colbert Busch won the Democratic nomination for the vacant seat. She'll face off against the victor of a runoff vote Tuesday night between two Republicans — former Gov. Mark Sanford and Charleston councilman Curtis Bostic. Polls show Sanford is likely to prevail in the runoff election.

The fundraising invite offered by Colbert references Sanford, dubbing the former governor a "renowned hike-lover." The swipe references the former governor's explanation that he was hiking the Appalachian Trail when he disappeared out of contact for days in 2009. It was later revealed Sanford was in Argentina carrying out an extramarital affair.

This is not the comedian's first fundraiser for his sister. During an appearance on "Late Night with Jimmy Fallon" in February, Colbert announced he would be hosting a fundraiser at a South Carolina bowling alley.

"We're going to raise money in a bowling alley, because we're of the people," he quipped.