What will Shelly do? That has to be the biggest short-term question in the Republican race.

The Las Vegas billionaire and Gingrich bankroller Sheldon Adelson has let Newt Gingrich play with unlimited house money thus far. But Mr. Adelson is a businessman, as well as a committed friend of Gingrich and backer of Israel. The business case looks nonexistent for Gingrich. So how long does Shelly stick?

Santorum is asking conservatives to unite behind his candidacy. In my experience, there are two kinds of conservative activists, just as there are with liberals: crazy and pragmatic. The crazies may agitate more for Santorum than ever, but the pragmatic ones will want to know what happens in Las Vegas.

Mr. Adelson has suggested he might back Romney if Gingrich falters. But the best way to do that may be by continuing to underwrite Gingrich, thus draining Santorum. (Notice no one mentions Paul; it's still Ron's world.) A Newt Gingrich newly surrounded by people with badges and guns (Secret Service) plus new funds may be just the combination Mitt Romney needs. It feeds two important needs of Newt: ego and money.