Jonathan Cohn says no:
Candidates can certainly improve with time. (I recall very distinctly then-candidate Barack Obama flubbing the first presidential forum on health care reform.) But there’s a broader lesson here. As I wrote earlier, Romney’s flaws are pretty much priced into his stock right now. He’s been under close scrutiny ever since the last presidential election. Pawlenty, Huntsman, and the other major contenders are still new at this. Nobody has dug through their pasts. Nobody has cross-examined them about positions. Nobody has seen how they deal with the rigors of a presidential race.
Jonathan Chait counters:
I agree that somebody has to win the nomination. I don’t agree that Romney’s faults are priced into his stock. I think the “stock” frequently takes a too-static view of candidates, overweighting things that can be measured at the moment, like name recognition and money, and under-weighting things that can’t, like how the process of electoral competition will alter the voters’ perception of them.
Jonathan Bernstein moderates.
The Dish 