“Rep. Nancy Mace announced Monday that she will not run for the South Carolina Senate seat held by the late Lindsey Graham,” Politico reports.Said Mace: “I’m not running for the U.S. Senate, not because I’m backing down from a fight, but because the one I’m already in matters right now.”“Her decision comes after a fifth-place primary finish in her run for governor earlier this year and as the race to succeed Graham is already taking shape.”