Isn't the immunity the Big Thing being compromised about?
If he rejects immunity, this is tantamount to rejecting the compromise - but he claims to be embracing the compromise.
So - he's misleading someone. Either he's misleading the Broders of the world with the headline, hoping to earn more "centrist" love - or he's misleading us in the last paragraph, putting up some nice words about rejecting amnesty when he knows full well that it would wreck the compromise.
I hope he's serious about killing retro immunity - but we'll see.
Nate Silver has pointed out that there's a strong correlation between nationwide and state-by-state results. No state will be polled as frequently as the whole country, so these national polls serve as a nice guideline for where we can expect the states to be (relatively).