Is this going to be the next theme of attacks on Obama?

That, if he isn't elected, blacks will riot in the streets? We already heard it from Jonah Goldberg, but since then I don't think it was mentioned much. But now we're hearing the same thing from Tom Sullivan:

Let me put it to you a different way. What if Barack Obama is not -- does not win the Democratic nomination, or he does win it, and loses in the presidential race against John McCain? Is black America going to throw their hands up and say, "Man, you know, I thought we were getting somewhere in this country, but this is just a bunch of racial bigots in this country and they still hate blacks and, I mean, if Barack Obama can't get elected, then we're never gonna have anybody that's a black that's gonna be elected president." And will there be riots in the streets? I think the answer to that is yes and yes.