COLUMBIA, S.C. - Myrtle Beach state Sen. Luke Rankin plans to switch to the Republican Party, South Carolina GOP officials said Tuesday. Rankin has served District 33 as a Democrat since 1993. In an open letter to the residents of Horry County, Rankin wrote that he has considered which party affiliation would allow him to best serve his constituents. "Because of recent rules changes in the South Carolina Senate, which require key leadership positions and committee assignments based on party affiliation as well as seniority, I am now certain that the needs of Horry County can be better served if...