DETROIT — 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 percent-22 percent, with Mike Huckabee in third at 16 percent, the poll showed.

Of the 40 percent who named the economy as their top concern, Romney had a 42 percent-25 percent advantage over McCain. McCain wins by about the same margin over Romney among the 24 percent 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 percent of voters who had a favorite said they might change their mind by Tuesday. Another 22 percent hadn't picked a candidate.

The telephone survey of 600 people who said they definitely will vote has a margin of error of plus or minus 4 percentage points. It was conducted Wednesday through Friday.

On Tuesday's Democratic ballot, only Hillary Clinton's name will appear among three major contenders. Barack Obama and John Edwards took their names off because Michigan violated national party rules by moving its primary before Feb. 5.

It's not known how many Democrats who are unhappy with their choices will choose to vote on the Republican ballot. Obama and Edwards supporters are urging a vote for "uncommitted."