As long as we're talking about Newt's profound conquering of Arizona, Nate Silver looked at Gingrich's odds of winning the GOP nomination earlier this month. The takeaway:
Overall, I would read three of these factors, establishment support, personal liabilities, and (especially) fund-raising, as being clearly negative for Mr. Gingrich. This contrasts against one, ideological positioning, which is potentially favorable for him. He has both strengths and weakness in the key early-voting states, meanwhile.
That balance is unfavorable enough to suggest that his chances of winning the nomination are weaker than his polls alone would imply. That certainly does not mean that his chances are zero, or 1,000-to-1 against. If Republican voters decide that they really don’t want to nominate Mitt Romney, Mr. Gingrich could be the last man standing. But even if Mr. Gingrich continues to gain in the polls, he will have some major weaknesses to overcome.
At the Daily Dish, Sullivan unloads on Newt:
It is the latest abject humiliation for Mitt Romney, as yet another unelectable clown becomes the front-runner. It's not often I agree with Paul Begala, but the Democrats must be somewhat aghast at their good luck. Check out the favorable/unfavorable polls on Gingrich assembled here. Republicans like him, but not without some severe doubts. But the general public really doesn't. His best rating is a negative 3. More typical is a negative 16. Even Rasmussen's white/GOP-leaning sample backs Obama over Gingrich by 6 points, with Pew and Quinnipiac showing Obama's lead in double digits.