Late-entry candidates and brokered conventions have not occurred in the recent past. But there has also not been a case in the recent past in which a candidate like Mr. Gingrich, so vehemently opposed by party elites, was surging ahead in key national and state polls at this stage of the nomination process.

To be sure, drafting a candidate like Mr. Daniels would be incredibly risky for Republicans. The candidate could be a failure on the stump. The move could be seen as a power grab, further widening the divide between the party establishment and the rank and file. It could backfire by cutting Mr. Romney’s support out from under him, resulting in the nomination of Mr. Gingrich. It would almost certainly give more of a role to Ron Paul, who will control some delegates and whom Republican elites also dislike. And because party nominating rules and ballot access rules have not been put to the test in recent years, there are “unknown unknowns” in addition to these obvious risks.

It is important to note, however, that party elites may also see a lot of upside potential in this scenario. It would not just be a ploy to prevent Mr. Gingrich’s nomination. It would also open the door to the party’s nominee being someone like Mr. Daniels or Mr. Bush or Mr. Ryan — candidates whom some influential conservatives have preferred to Mr. Romney all along.