Ed Rendell: Sanders Supporters Better ‘Behave Themselves’ at the DNC

"I think it’s going to be a great convention, but of course, the key to it is the Sanders people. Bernie’s going to have his name placed in nomination; we're going to have a roll call; there’s going to be a demonstration in support of Bernie; he’s going to lose the roll call. His supporters have to behave and not cause trouble. And I think they will. And I think Senator Sanders will send them a strong message."