Republican presidential candidate Donald Trump disavowed white nationalist and former Ku Klux Klan grand wizard David Duke in a tweet Sunday. "As I stated at the press conference on Friday regarding David Duke- I disavow." Earlier Sunday morning, Trump avoided a question about whether he'd condemn Duke's racism. The GOP front-runner said on CNN's "State of the Union" he didn't know anything about Duke and would need to research his connections before deciding whether he would condemn them. "I have to look at the group. I don't know what group you're talking about," he said. "You wouldn't want me to...