There does seem to be a schism appearing within both parties concerning Iran?

I assume that any schism we're aware of is part of the show. As Chomsky said, there's a news hole, and you have to fill it every day or people worry. In reality, they'll do what they want to do about Iran and about everything else. Not that they aren't concerned about public opinion; they are, because they love us and want us to be happy. But that concern translates into shaping opinion rather than shaping policy.