If Romney campaigns in MN it wont look like he is a momentum candidate expanding the map, it will look like he is a desperate candidate trying to find a path around Ohio.
Seriously?
1) I think any rational person will agree that if Romney wins Minnesota of all states, he wins Ohio with ease. Minnesota is a tier 2 state to any Republican win. (Akin to NC going into the D camp, you'd be looking at a 300-350 EV scenario).
2) Virginia is pretty much closed off to campaigning for a few days.
3) It's not like Romney can't do a MSP-suburbs/pick a city in Wisconsin two-stopper with ease.
4) Any trip into the MSP area, will be beamed into Northwestern WI. It's a two-fer.
5) Expanding the map and making your opponent play defense is NOT a bad tactic. Especially when your opponent may be stuck in DC for a few days being President.
The time for Romney to expand the map was 2 weeks ago when he had momentum and he was polling ahead in at least half of the battleground states but since then things have been flat or receding and his OH problem looms larger and larger and so a move into MN will be seen more as a way around his OH problem and not really expanding the map. Or that is my bet on how the MSM would cover it