Count the Land of 10,000 Lakes as a new battleground state. According to the Star Tribune Minnesota Poll, John McCain has caught Barack Obama and has put the state in a dead heat among likely voters. McCain has reversed a 13-point deficit from May and has forced Obama to start spending in what looked to be a solidly blue state:

Minnesota has become a battleground in a presidential campaign that has dramatically tightened nationwide.

A new Star Tribune Minnesota Poll shows that the race is now a dead heat between Barack Obama and John McCain, each supported by 45 percent of likely voters in the state. …

The poll found that McCain has made gains across the board since a May Minnesota Poll that showed him trailing by 13 points. He has picked up considerable support among men and to a lesser degree among women. He also has boosted his standing with whites, young voters and all levels of household income and education.

The selection of Sarah Palin hasn’t directly affected the numbers in Minnesota, at least not yet; the Strib’s internals look like a wash. However, it may have had an indirect effect similar to that seen nationally in the latest AP poll. While 45% of voters think Palin lacks enough experience for the job, 44% now think the same thing of Obama. Palin and Biden have contradictory numbers. Many more see him as experienced enough for the job, but Minnesotans like her better than him by nine points.

One of the more striking numbers from the poll is the younger voter demographic. Obama has had a large lead in most polling in voters under 35, and in Minnesota, the college-age and young adult vote is a formidable weapon. Now, though, McCain and Obama evenly split that vote, which bodes ill for Obama in a general election.

If Minnesota becomes a battleground, it’s yet another place Obama now has to shift to defense. It signals that the empty populism of the primaries has worn too thin in the general election, and even a state that voted for John Kerry by four points over George Bush has doubts about Kerry’s successor. It’s another in a series of bad signs for Team Obama.