Candidates like Mr. Rubio, Mr. Walker, Mr. Kasich, Rick Perry, Mr. Christie and Rand Paul can compete for moderate and independent voters in New Hampshire, a state that Mr. Bush may need to win. On paper, one would expect that a relatively moderate Republican would fare well in New Hampshire. But Mr. Bush has struggled to take a lead there, and it’s fair to wonder whether he is as good a fit for the state as one might guess from his moderate reputation.

The state’s voters aren’t just relatively moderate; they’re independent and iconoclastic. John McCain won the state in 2000 and 2008, while Jon Huntsman and Ron Paul combined to amass more support than Mr. Romney received four years ago. One wonders whether an establishment-backed Bush is the right candidate to appeal to a state with a penchant for “mavericks.”

Just as important, the field includes candidates who have the potential to consolidate conservatives without alienating the rest of the party. The inability of conservatives to get their act together has been one of the biggest assets to the establishment. In the last two Republican primaries, conservatives settled on two evangelical favorites — Mr. Santorum and Mike Huckabee — who had little chance of defeating the more mainstream front-runner in a long battle.

This year, both Mr. Walker and Mr. Rubio have the potential to consolidate conservatives and win a national campaign.