Romney admits mistakes in campaign Mitt Romney has admitted he made "mistakes" in his campaign for the 2012 Republican nomination and attacked his chief rival Rick Santorum for "dirty tricks," on the eve of the crucial Michigan primary on Tuesday. He also said he would not "light my hair on fire" for conservatives to win their votes, adding the quip that there would be a "big fire" if he did, in a reference to his healthy head of hair. The rare admission of error and the attacks on Mr Santorum from Mr Romney underline the closeness of the Michigan race and the longtime front-runner's nervousness that he could lose a state he was considered certain to win. Mr Romney said Mr Santorum had showed his desperation in making automated phone calls to registered Democrats in the state to vote in the Republican primary, as they are allowed to do. In the automated calls, Mr. Santorum's campaign said: "Romney supported the bail-outs for his Wall Street billionaire buddies but opposed the auto bail-outs. That was a slap in the face to every Michigan worker and we're not going to let Romney get away with it. Mr Romney said at a press conference: "I think Republicans have to recognise there's a real effort to kidnap our primary process. And if we want Republicans to nominate the Republican who takes on Barack Obama, I need Republicans to get out and vote and say no to the, the uh, dirty tricks of a desperate campaign. The latest polls put Mr Romney neck and neck with Rick Santorum, his socially conservative rival, although he appears on course to win a resounding victory in Arizona. Mr Romney, who was born and raised in Michigan and whose father was a popular state governor, has been campaigning vigorously in recent days as he tries to mobilise support before Tuesday's primaries. "I am going to win in Michigan and I'm going to win across the country," Mr Romney said at a campaign stop on Monday. But he faces continued scepticism from the Republican party's conservative base, who view the former Massachusetts governor as too moderate. Mr Santorum, who has strong support among Christians and the Tea Party movement, also voiced optimism. "I think we're going to surprise a few people tomorrow [Tuesday] night," he said at a rally in Kalamazoo. Polls released over the past two days show Mr Romney and Mr Santorum are tied. Voting ends in many areas at 8pm EST and results are expected to start coming through shortly afterwards. Mr Romney has had a sizeable lead in polls in Arizona, where he has been endorsed by John McCain, the state's senior senator and previous Republican presidential nominee. Arizona is the more important of the two primaries from a technical point of view. It will award all 29 of its delegates to the winner of Tuesday's vote, while Michigan will used a proportional system that will see its 30 delegates shared among the candidates, meaning none is likely to sweep the table. Each of Michigan's 14 congressional districts will award two delegates to the winner in its district. Mr Romney is performing strongly in the seven urban districts around Detroit, while Mr Santorum is ahead in rural parts of the state. The remaining two delegates will be awarded to the winner across the state, but the closeness of the vote suggests Mr Romney and Mr Santorum will be awarded one each. A candidate needs 1,144 delegates to clinch the nomination before the Republican party convention in late August. Mr Romney is ahead with 123 delegates so far, while Mr Santorum has 72. Newt Gingrich, the former House speaker, has 32 and libertarian Ron Paul trails with 19. In addition to the 59 delegates to be awarded on Tuesday, another 413 will be awarded on "Super Tuesday" next week, when states including Georgia, Ohio, Oklahoma, Tennessee and Virginia will vote. Although Arizona is more important for delegate count, a loss in Michigan would come as a bitter blow for Mr Romney, who has portrayed himself as a native son of the state and has sought to show how cars - the economic linchpin of the state - are in his blood. His father was head of the American Motor Company before becoming governor. A win for Mr Romney would put him back in the lead, although he would continue to have to fight for every race in what is shaping up to be a protracted battle. A loss, on the other hand, would underline the misgivings that the party base continues to have and could trigger a search for a new candidate with the ability to take on President Barack Obama in November.