With the economy taking center stage in Michigan, a new Detroit Free Press poll shows Mitt Romney narrowly in front of John McCain 27%-22% with Mike Huckabee in third with 16%.

Republican primary voters whose greatest concern is the economy could give Bloomfield Hills native Mitt Romney his first major state victory in Tuesday’s Michigan presidential primary, according to the Detroit Free Press-Local 4 Michigan Poll.

Romney leads John McCain, 27%-22%, with Mike Huckabee in third at 16%, the poll showed. Romney’s core of support is in metro Detroit, where he has a 2-1 advantage.

Of the 40% who named the economy as their top concern, Romney had a 42%-25% advantage over McCain. McCain wins by about the same margin over Romney among the 24% of Republican voters whose top issue is the Iraq war. But Romney's lead could evaporate, depending on how tentative, undecided and uncommitted voters lean over the next two days.

About 38% of voters who had a favorite said they might change their mind by Tuesday. Another 22% hadn't picked a candidate. The poll also shows that relatively few Democratic voters plan to vote in the Republican primary, a factor that may be difficult to gauge. Independents and Democrats who cross over to the GOP could tip the election to McCain if they show up in substantial numbers.