Romney and Santorum in tight race in Michigan SOUTHFIELD/GRAND RAPIDS, Michigan (Reuters) - Mitt Romney and Rick Santorum were neck and neck as votes trickled in from Michigan's Republican presidential primary on Tuesday, with Romney fighting to avoid a humiliating defeat in the Rust Belt State where he grew up. With 25 percent of precincts reporting, Romney led Santorum by 41 percent to 38 percent. Texas Congressman Ron Paul claimed 11 percent and former House Speaker Newt Gingrich had 7 percent. In Arizona, Romney rolled to an easy victory. Television networks declared him the winner there as soon as polls closed at 9 p.m. EST (0100 Wednesday GMT). But the stakes are particularly high for Romney in Michigan, where he was born and raised and where his father was a popular governor in the 1960s. A defeat would raise more questions about the one-time front-runner's ability to appeal to conservatives and blue-collar voters in the state-by-state battle to take on Democratic President Barack Obama in the November 6 general election. Arizona awards its 29 delegates on a winner-take-all basis, while Michigan awards its delegates on a proportional basis. Santorum's campaign appealed to Democrats in the primary, criticizing Romney for opposing the government's 2008-2009 rescue of the domestic auto industry, which is based in Detroit. Santorum, opposed the bailout as well. An exit poll showed Democrats accounting for 10 percent of the vote, more than in 2008 but less than in 2000. Writing by Andy Sullivan; Editing by Doina Chiacu