Rep. Nancy Mace (R-S.C.) said in an interview that she thinks she will win reelection despite being opposed by President Donald Trump, whose endorsement or opposition carries substantial weight among GOP voters. On Jan. 15, Mace told South Carolina’s The State newspaper “I’m gonna win without [Trump].” Mace’s comment comes after Trump on Feb. 9 threw his support behind GOP primary challenger Katie Arrington. In 2018, Arrington successfully unseated long-serving congressman and former South Carolina governor Mark Sanford, winning the GOP nomination to challenge former Rep. Joe Cunningham (D-S.C.) in South Carolina’s first congressional district, which comprises Charleston and its environs. The surprise primary victory came after a public feud between Sanford and Trump. However, Arrington was narrowly defeated by Cunningham in the general election by a 1.4 point margin. In his endorsement of Arrington, Trump blamed the defeat on a bad car crash right before the election that left Arrington …