A few questions remain to be answered. Enter Mitch Daniels? Exit Sarah Palin?
But already two of the best-known candidates seem bent on ruling themselves out of contention.
One is Newt Gingrich. He's being denounced for his comments on House Budget Committee Chairman Paul Ryan's Medicare plan by the likes of Rush Limbaugh, Bill Bennett, the Wall Street Journal editorial page and Charles Krauthammer on Fox News.
Ryan's Medicare plan was part of the budget resolution that all Republicans but four voted for in the House. It is for all practical purposes the platform of the Republican Party. And Gingrich seemed to trash it.
He did so in response to a tendentious question from "Meet the Press's" David Gregory, who asked whether Republicans "ought to buck the public opposition" and "really move forward to completely change Medicare."
The smart response would have been to challenge the premises of Gregory's question. The Ryan plan is not necessarily unpopular -- public sentiment depends heavily on how poll questions are worded. And the plan wouldn't completely change Medicare. The current system would remain in effect for everyone now 55 and over.
But Gingrich accepted Gregory's premises. "I don't think right-wing social engineering is any more desirable than left-wing social engineering," Gingrich responded. "I don't think imposing radical change from the right or the left is a very good way for a free society to operate."
So a former Republican speaker of the House who wants to become a Republican president has just given Democrats a warrant to label a major Republican proposal "right-wing social engineering" and "radical change from the right."
It's not hard to see why Russell Fuhrman, an Iowa Republican who happened to run into Gingrich in Dubuque, said: "You're an embarrassment to our party. Why don't you get out before you make a bigger fool of yourself?"
From his own personal experience, Gingrich should have known what is happening here. The party's congressional wing, with its majority in the House, has taken the initiative in setting party policy -- as it did when Gingrich was speaker in 1995 and 1996.
Republican presidential contenders didn't disparage Gingrich's ideas in anything like the way Gingrich disparaged Ryan's. Gingrich sees himself, accurately, as a generator of new ideas. But the party he seeks to lead is already committed to ideas that are apparently contrary to his.