I can see how someone who might normally root against Texas be cheering in favour of them here, because they are the underdog against the dominant defending champions. Nebraska was the total opposite: due to their total assraping of anyone and everyone, if you weren't a fan of them you couldn't help but hate them (although I was pulling for them to win the championship in 1994, just so PSU wouldn't). Cheering for mid-90s Nebraska would be like a UCLA fan cheering for this year's USC.
Okay, I'll buy that one...
How about this example: Ohio State in '02 with all their lucky wins and coming into national prominence with Tressel after years of John Cooper holding them firmly in "so close yet so far" territory.
A good story (I suppose), but I can't see many Michigan fans who were rooting for them in that instance. I know I sure as hell wasn't.