In the short run, Mr. Gingrich must temper runaway expectations. For example, his lead in the RealClearPolitics average in Iowa is 12 points. But what happens on Jan. 3 if he doesn’t win Iowa, or comes in first with a smaller margin than people expect?

That could happen in part because Mr. Gingrich has little or no campaign organization in Iowa and most other states. He didn’t file a complete slate of New Hampshire delegates and alternates. He is the only candidate who didn’t qualify for the Missouri primary, and on Wednesday he failed to present enough signatures to get on the ballot in Ohio. Redistricting squabbles may lead the legislature to move the primary to a later date and re-open filing, but it’s still embarrassing to be so poorly organized.

Organization truly matters, especially in low-turnout caucuses. Four years ago, for example, 118,917 Republicans turned out in Iowa—and only 424 votes separated the third- and fourth-place finishers. The total turnout was considerably less than the 229,732 Iowans who voted in the GOP primary for governor two years later. Being organized in all 99 Iowa counties means more people can be dragged to caucus meetings who might otherwise stay home on a wintery eve, believing their vote doesn’t matter.