Former congressman and former South Carolina Gov. "We're at a tipping point, and that's why I've decided to run for the U.S. Senate," Sanford said in a launch video. Advertisement AdvertisementBut Trump's backing of the late senator's sister isn't stopping other well-known South Carolina Republicans from jumping into the contest. "Senate seats in South Carolina do not come up very often, and politics is all about timing. Original article source: Trump endorsement fails to clear GOP field as former governor joins South Carolina Senate race