Maybe not this time. In state elections, Minnesota Republican caucus-goers have tilted far to the right, with many strong right-to-lifers -- a group more likely to favor Santorum or Gingrich than Romney. Colorado's caucuses have a lesser conservative tilt and look pretty safe for Romney.
Those caucuses are non-binding; so is Missouri's primary on the same day. Missouri was a tight three-way race last time, and Romney did well in the two big metro areas that cast about half the vote. Gingrich is not on the ballot, so Santorum has a chance to shine in the rest of the state where Romney ran weakly.
Finally there are the Michigan and Arizona primaries on Feb. 28. Michigan is Romney's native state, where his father was elected governor when he was in 10th grade, and he won there in 2008.
A Michigan poll taken in the days after South Carolina showed Romney leading Gingrich by only 5 points. There's no recent polling in Arizona.
Many analysts see February as a Romney sweep month. I'm not so sure. We may see among Republicans a phenomenon apparent in the 1980 and 1992 Democratic cycles: When a candidate who is not hugely popular seems to have a nomination clinched, people with qualms start voting for whoever else is still campaigning.
Romney is seeking to lead a party fired up by opposition to the Obama Democrats. He has campaigned with a feisty spiritedness that is at odds with parts of his record and often with his temperament.
He has succeeded in large part because the only ideologically pure candidate, Michele Bachmann, lacked stature, and his more experienced rivals lacked purity.
In Florida, Romney showed fire, drive, energy and a willingness to attack, and carried just about every segment of the electorate. Unlike his rivals, he has maintained competitive general-election numbers in this largest of target states.
Florida provided a benchmark win, but more tests lie ahead.