This scenario assumes that Mr. Romney will win Massachusetts and Virginia very easily, and Vermont and Idaho fairly easily (winning all 32 delegates in Idaho because of the way the state’s rules are structured). It assumes a narrow Romney win in Ohio and a narrow loss in Tennessee, and that Mr. Romney wins either the Alaska or North Dakota caucuses, but probably not both. Mr. Gingrich wins Georgia only, although by a big margin; Mr. Santorum wins Tennessee and Oklahoma, although by smaller margins than were expected a few days ago.

If the evening goes exactly according to this plan — of course, it probably won’t — that would leave us in something of a predicament. Mr. Romney, by any objective measuring stick, would have had a good night, winning more than half the delegates and at least half the states — including Ohio, a state that inherently isn’t all that favorable to him.

But, as Mr. Romney’s position has improved in the polls, expectations have risen as well. The news media have been focused on three contests — Georgia, Ohio, Tennessee. Of these, Mr. Romney would win just one, and then by a margin that might not be called until fairly late in the night.