Why did Obama do better in PA, MI, WI than in MN in 2008 (by a lot in MI, WI)

[TJ in Oregon]

The reason for the MN/WI trending divergence was primarily because the McCain campaign decided to dump a ton of money into Minnesota. I remember reading somewhere that Minnesota was the only state in the country where McCain outspent Obama. Somewhere in the upper echelons of the GOP brass, somebody thought Minnesota was the pathway to victory.

Further evidence of this can be seen in the 2008 Wisconsin trend map:


You can see that everywhere in a Minnesota media market trended R and more or less everywhere else trended D.