The problem is that at GMU, it is a commuter school, even though they’ve built some dorms in recent years (I am from Fairfax) and if you haven’t noticed, there are many foreigners who attend school there.
A better test would be GW, UMD-College Park or Georgetown, which, I would presume to be be a minimum of 75% Obama.
All the aforementioned colleges have a lot of resident students whereas GMU, as you noted, has many parking lots to accomodate commuters.
My take.
I was just in Georgetown Tuesday and it was more like 100% Obama. I didn't see one McCain sign/sticker.