The rise of Newt Gingrich in Iowa, New Hampshire and nationally is real. The question, of course, is whether it can be sustained. No one really knows at this stage. But what is clear is Gingrich presents the most serious challenge the Romney campaign has yet faced.

None of the other candidates who have risen in the polls to challenge Gingrich– Bachmann, Perry or Cain — possess his political skills, which are considerable. And none can match his past political achievements, which are impressive. One has the sense that unlike the others, Gingrich at least belongs in Romney’s weight class. Which means this could be a real contest.

Governor Romney still has to be considered the favorite, at least based on the usual political metrics (money, early-state organizations, staff professionalism, etc). Romney has become a formidable candidate, including an excellent debater. For moderate-leaning GOP voters, whose numbers are not inconsiderable, Romney is the clear choice. And Gingrich has accrued a lot of what’s commonly referred to as “baggage” these days. As I’ve argued before, now that he’s considered a front-runner, the intensity of the coverage of Gingrich — never a media favorite to begin with –will be enormous. And like the others, Gingrich might wither away.

Still, Gingrich has played in the big leagues for many years now. He has the capacity to inspire conservatives in a way that Romney, at least so far, has not. He possesses an active and creative (if impulsive and sometimes unrestrained) mind. And Gingrich understands, at least intellectually, his past weaknesses, including his lack of discipline and propensity to use strident, even apocalyptic, language.

To prevail, we would have to see a “new” Gingrich. Whether a man at Gingrich’s age can re-make himself is an open question. I have my doubts. But Gingrich now has his chance to prove me, and others like me, wrong.

Stay tuned.