Voters in the US state of Michigan are gearing up for the Republican primary on Tuesday in the next stage of the race for the White House.
Michigan could be make-or-break for Mitt Romney, analysts say
Polls suggest a very close battle between Arizona senator John McCain and local boy Mitt Romney.
The Democratic contest has been weakened because Michigan chose to hold its vote early and the party barred its delegates from the final convention.
Analysts say Michigan's fragile economy is the main issue.
The state and its main city Detroit used to be famous for making cars.
But Michigan has been hard hit by a downturn in the automobile industry, and now has the highest unemployment rate in the US at 7.4%.
Some commentators say the primary could be crucial for former Massachusetts governor Mr Romney, who failed to win in New Hampshire and Iowa despite heavy spending.
Michigan had Mr Romney's father, George, as its governor from 1963 until 1969. Mitt Romney's wife was also born in the state and in eve-of-poll campaigning he has been stressing his local roots.
"The auto industry and all its jobs do not have to be lost," he told an audience in Detroit on Monday.
"And I am one man who will work to transform the industry and save those jobs."
An average of polls suggests that Mr Romney is marginally behind Mr McCain, who won the state in his presidential bid in 2000 and won the New Hampshire primary last week.
Mr McCain is seeking to build on that success by aiming his comments at struggling workers, promising to help retrain them if he is elected president in November.
"We're not going to leave these people behind. That's what America is supposed to be all about," he told students at Kalamazoo on Monday.
Third in the polls is former Arkansas governor Mike Huckabee, who won the Iowa caucus.
In a rally in Augusta, he said was the only Republican candidate who understood the struggles of working-class people in Michigan.
Other big names, like former New York Mayor Rudy Giuliani and former Tennessee Senator Fred Thompson, are not taking part in Michigan, holding their fire for later in the national campaign.
In the Democrat race, only Hillary Clinton of the leading candidates features on the ballot.
Barack Obama and John Edwards took their names off last October, after the national party penalised the state party for holding its primary early.
Most Democrats are focusing their energies on the contests in Nevada on Saturday and South Carolina on 26 January.