Michael Barone‘s latest column delves into Republican presidential contender Mitt Romney’s next steps after this week’s Florida primary win.

The first February contest is the Nevada caucuses on the fourth. Romney won easily four years ago, thanks in part to the high turnout of his fellow Mormons. But the Nevada caucuses had never been held before, and turnout was a low — 44,000 in a state of 2,700,000 people.

It’s likely to be higher this time, with a lower Mormon percentage, and in a state where Republican primary voters chose Sharron Angle in 2010.

The Maine caucuses start, but don’t finish, on February 4. Romney forces are confident there, but Maine Republicans nominated and elected a very conservative governor in 2010.

Three days later, on February 7, come the caucuses in Minnesota and Colorado. Romney won both in 2008, when he was the only Republican candidate with much of a caucus organization.

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. …

… 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.