Obama leads Romney 47 percent to 46 in the poll, which has a 3.5 percent margin of error. It’s the fourth poll in June to show the candidates neck and neck in the Wolverine State, which has swung reliably Democratic in recent elections and where Obama was up by double digits as recently as mid-May.

“Obama will have to campaign very heavily in Michigan, something he did not want to do,” said Mitchell Research Chairman Steve Mitchell in a statement. “Every dollar he spends here is a dollar he will not have in Ohio, Florida, Colorado, Virginia and other states crucial to his election. Unlike 2008, when John McCainJohn Sidney McCainGraham: Trump can make GOP bigger, stronger, or he 'could destroy it' Former Trump Defense chief Esper to join McCain Institute We need an independent 1/6 commission that the whole country can have confidence in MORE publicly announced he was not campaigning in Michigan, Romney and Obama will likely be battling all the way to Nov. 6.”

Obama still leads by 3.5 percent in Michigan, according to the Real Clear Politics average of polls, but he’s boosted in part by a survey from conservative polling outlet Rasmussen, which shows him up by 8, and which now looks like an outlier.

Romney’s father, George Romney, was once governor of Michigan, and Romney spent his childhood there, but many didn’t believe the former Massachusetts governor would devote significant resources to a state Obama won by 16 percent in 2008.

Romney barely won the state’s Republican primary earlier this year, edging competitor Rick Santorum by 3 percent, but effectively split the delegate count with him. At the time, many called it a blown opportunity for the former Pennsylvania senator, who got wrapped up in controversial social issues just prior to the primary.