When he was just the topic du jour because of his question to Barack Obama back in the neighborhood in Ohio, that was one thing. But "Joe the Plumber" is now actively campaigning with and for John McCain, appearing on stage with him at multiple events, etc. He has become a part of McCain's campaign, like any other surrogate.
So here "Joe" is on TV just about an hour ago saying that people shouldn't vote for Obama because he doubts Obama's "loyalty to America".
I guess saying Obama reminded him of Sammy Davis, Jr. wasn't bad enough. But isn't it time someone ask McCain whether he's really willing to associate with this extremist?