Republican candidate Mitt Romney has won the Michigan primary, beating rival Sen. John McCain and establishing himself as a major contender ahead of Saturday's race in South Carolina.

"Tonight marks the beginning of a comeback --- a comeback for America," Romney told a roaring crowd of supporters.

"Let's take this campaign to South Carolina and Nevada and Florida and all over the country. Let's take it all the way to the White House."

With 86 per cent of polls reporting, Romney had 39 per cent support while McCain trailed with 30 per cent.

Former Arkansas Gov. Mike Huckabee, who won at the Iowa caucuses, was third with 16 per cent.

Romney, former governor of Massachusetts, had hoped his status as a native son in the state would give him an edge.

He had finished second in Iowa and New Hampshire, but won in Wyoming. With deep roots in Michigan, his father George having served as the state's governor for three terms in the 1960s, some observers had speculated that another loss might have fatally wounded his candidacy.

On Saturday, the Republicans will head to South Carolina for the state's primary. Democrats will have their primary one week later.

Earlier Tuesday Romney had said he was expecting a win.

"Michigan is going to vote for a Romney again!" he declared at a rally in Grand Rapids.

Michigan's Republican primary was open, meaning Democrats and independents could cast ballots for Republican candidates.

McCain won Michigan during his failed presidential 2000 bid, largely on the strength of independent voters.

Turnout was expected to be about 20 per cent. Temperatures were below freezing and some parts of the state had received up to 15 centimetres of snow by early morning.

The economy was expected to be a major issue for voters.

Michigan has been the traditional home of the U.S. auto industry, and downsizing in that sector has ravaged the state's employment base. The unemployment rate of 7.4 per cent in November was the highest in the United States.

McCain tried the straight-talk approach, telling people that many of the auto sector's jobs are gone for good. His prescription to boost U.S. competitiveness is to cut taxes and reducing government spending.

But Romney told voters that the auto industry could be salvaged.

"The pessimists are wrong," Romney told the Detroit Economic Club on Monday.

"The auto industry and all its jobs do not have to be lost. And I am one man who will work to transform the industry and save those jobs."

Democrats

Hillary Clinton was the only name on the Michigan Democratic primary ballot. The state moved its primary to Tuesday from its usual date in February in an attempt to make the state more influential.

The Democratic party stripped Michigan of all its national convention delegates (the Republicans lost half), although state party leaders say they are confident the delegates will eventually be seated.

However, Barack Obama and John Edwards, two of the other top Democratic candidates, pulled their names off the ballots.

With 88 per cent of polls responding late Tuesday night, Clinton won 56 per cent, and 39 per cent of the votes were independent.

With files from The Associated Press