Evidently, Romney is not seen as totally unacceptable by tea party sympathizers and has a considerable advantage on electability.
The race now goes to New Hampshire next Tuesday and South Carolina on Jan. 21. Santorum, who has had negligible support in New Hampshire, will surely get a bounce from his late surge in Iowa, but the Granite State has a much more secular electorate and Romney's big lead in the polls there seems to be strongly based.
Paul will get a share of the non-Romney vote and so may Jon Huntsman, who skipped Iowa and staked his all on New Hampshire.
The old saying is that three candidates get a ticket out of Iowa to New Hampshire. One who didn't, Perry, says he will go on to South Carolina instead.
Gingrich, who once looked to be competitive with Romney in New Hampshire and had a big lead in South Carolina polls before Christmas, will undoubtedly soldier on and hope he can reverse his slide with good debate performances.
It is too soon to say that Romney has a clear flight path to the nomination. But the tensions between his past record and current tea party orthodoxy have not proven to be disabling, because the other candidates are to varying extents out of line with that orthodoxy, as well.
Romney has had the benefit of luck -- several strong competitors declined to run or dropped out -- but also showed skill in deciding last month to ramp up his Iowa campaign. But he has yet to show he can beat an opponent one-on-one.