Any particular reason why Colorado is about the only swing state that is (or appears to be) swinging towards Romney?
One reason may be the very same reason that Ohio and Michigan are actually swinging back towards the president: Bain. The whole class warfare business works well against a wealthy, moderate, northeastern Republican among blue-collar independents and even Republicans in the working class burghs of the Midwest. It's a completely different electorate in Colorado, where the president is extremely unpopular and Romney's suburban politics hit a sweet spot in and around Denver.
I wouldn't be at all surprised to see Romney win Colorado, and lose most of the other so-called "swing states."
And, I'll add, Colorado has always been more of a right-leaning swing state, anyway. So perhaps it shouldn't be that surprising after all.
Except that Ohio and Michigan aren't actually swinging toward Romney. They've both moved noticeably towards Obama in the past month or so:
http://www.realclearpolitics.com/epolls/2012/president/oh/ohio_romney_vs_obama-1860.html
http://www.realclearpolitics.com/epolls/2012/president/mi/michigan_romney_vs_obama-1811.html
No, you misunderstand, he's admitting that it's working in Ohio and Michigan but saying that it's a different story out in Colorado.
Whoops, misread that. Sorry!
Anyway, I don't think there's any evidence that Colorado is moving towards Romney, either.
If you compare like polls with like, there's been very little change in the last few months in Colorado -- Rasmussen has had the race tied, PPP has had Obama up by 6 or 7, Purple Strategies has had Obama up by 1 or 2, or the race tied. We haven't had one of these CBS/NYT/Q-Pac polls of CO before, so it's hard to know how to read it, but given that the simultaneously-released PPP and Rasmussen polls show no change, I think it's unlikely that there's been much of a shift at all in CO.