Six -term Sen. Thad Cochran , James Lankford , holds off tea party challenger . Longtime lawmaker Charlie Rangel claims victory in tough Oklahoma primary . Rep. James Lankford wins McDaniel primary in New York . Coburn 's announcement in January that he would step down at the end of the year -- with two years left in his term -- sparked a competitive primary in Oklahoma to replace the conservative senator . GOP Senate weighing whether to challenge vote .
Six -term Sen. Thad Cochran , James Lankford , holds off tea party challenger . Longtime lawmaker Charlie Rangel claims victory in tough Oklahoma primary . Rep. James Lankford wins McDaniel primary in New York . GOP Senate weighing whether to challenge vote .