For Mitt Romney, campaigning in Michigan should be a happy experience of fighting on home turf. He grew up in Detroit and his father was the state's Governor and a top car executive.
As Romney touched down to woo Michigan voters in the next stage of his quest to become the Republican presidential nominee, he certainly treated it like a homecoming. At a rally in Grand Rapids, Michigan's second largest city, Romney even spied two former high school friends in the waiting crowd. "Any old girlfriends here?" he asked. "Got to be careful. Ann [his wife]'s not here today. Don't tell!"
But campaign humour - especially about his marriage - does not come naturally to the straitlaced Romney. The joke fell flat. Far from being friendly territory, Michigan is now shaping up to be a potential disaster.
As little as a week ago Michigan's vote on February 29 was seen as a "firewall" for Romney ahead of the vital "Super Tuesday" contests on March 7. It was a virtually guaranteed win that would let him wrap everything up a week later and become the presumptive nominee.
But former Pennsylvania senator Rick Santorum has swept into the state on the back of wins in Colorado, Minnesota and Missouri. Now he is ahead in all recent Michigan polls.
The social conservative and devout Catholic is also surging in national polls. In one poll in Ohio - one of the vital Super Tuesday states - Santorum is now beating Romney by 18 points.
Santorum's rise is based on an increasingly powerful blend of social conservatism with a hefty dose of blue-collar economic populism.
Santorum's working-class background is something he repeatedly emphasises on the campaign trail. He even talks up the idea of looking after the poor in troubled economic times.
Romney, who is busy trying to prove himself a fiscal conservative, has suffered an avalanche of scorn for his critical stance against the Government-helped bailout of the car industry at the height of the economic crisis. At the time, Romney said government help would kill America's car industry. Last week, he penned an editorial in the Detroit News slamming President Barack Obama as having sold out Detroit's "Big Three" car companies to their unions.
That is not a popular opinion in Michigan. Most people see the bailout as an unmitigated triumph with some experts saying it may have saved up to 1.5 million jobs in the state. Last week General Motors posted record profits and once again became the world's largest car maker, paying out hefty bonuses to its workers. "Romney is either a bad businessman, a lousy politician, or both," said Peter Cohan, a Forbes magazine columnist and business analyst.