 It was the first time he's been seen since being wounded in an assassination attempt over the weekend. He waved to the crowd, mouthed thank you, and sat for about an hour listening to people take to the stage. One of them, Teamsters Union President Sean O'Brien. Today, the Teamsters are here to say we are not beholden to anyone or any party. But he offered no endorsement. Matt Piper, CBS News, Milwaukee.