SOUTHFIELD, Mich. — John McCain sought to keep his momentum going strong. Mitt Romney looked to keep his candidacy afloat. And Mike Huckabee simply wanted to keep defying expectations.

No matter the winner, the Republican presidential primary in Michigan on Tuesday promised to add another wrinkle to a nomination fight that has defied a clear favorite.

Snow fell across much of the state, half a foot before noon in some places, threatening to dampen turnout that was already expected to be light. In the state of his birth, Romney voiced edgy confidence in his chances and so did McCain, who won Michigan in the 2000 primary race.

Outside a Baptist church in Warren, Mike Huckabee was happy to see the freezing temperatures and snowfall, reasoning that his evangelical base would come out to vote when others less committed might not. "That can only be good for us because I think most of our voters are very focused. We hope so, anyway."

Opinion polls indicated a tight race between McCain and Romney.

"I think it's going to be very close," McCain said before a rally at Northwestern Michigan College. The Arizona senator said his primary goal — beyond winning — was to attract Republican votes, but "having independent and Democratic votes shows potential for the general election."

Michigan voters can vote in either primary, regardless of their party registration.

McCain also toured a historic house converted to a funeral home, an odd twist for a man who believes in portents. But he wore a lucky-charm sweater — a green one he had on the day he won the New Hampshire primary.

In Grand Rapids, Romney told about 100 supporters gathered in the warehouse of an office furniture company: "I think Michigan is going to vote for a Romney again."

Romney again sought to differentiate himself from McCain and Huckabee by highlighting the private-sector experience Huckabee lacks and accusing McCain of achieving few results despite nearly three decades in Washington.

"People have been talking about things that Washington has been promising for years but not delivered," Romney told the crowd. "And so, I will go to Washington to stop the bickering, the sniping, the partisanship, the score-settling. I will go to Washington to actually get the job done for the people of America."

Huckabee won the Iowa caucuses, McCain prevailed in New Hampshire and Romney was second to both, while claiming victory in scarcely contested Wyoming. Fred Thompson, the former Tennessee senator, is camping out in South Carolina looking for his first win. Rudy Giuliani, the former New York mayor, is doing the same in Florida.