Romney has a lot of challenges now: (1) Perform really well in Monday's debate in Tampa; (2) find a negative frame he is comfortable driving against Gingrich himself personally, not through surrogates, that will be effective; (3) keep the Establishment types who are with him now from going wobbly; (4) convince the Establishment types who haven't yet committed to him to come on board at a time of weakness by raising the Newt-as-nominee specter; (5) stop making errors on the trail; (6) somehow put the tax returns issue to rest with care, precision and speed; (7) prove he can handle the kind of existential threat to his candidacy that he has avoided up until now. That's a tall order. He's still the favorite to be the nominee. But now, to borrow one of his campaign slogans, he is going to have to earn it.