Republicans actually did re-redistrict Colorado in 2003. They split Pueblo County to make the 3rd much more Republican, for one. A court overturned it before the 2004 elections, since the state constitution explicitly bars redistricting more than once per decade.
For Louisiana, maybe Kerry got some of the white Catholic vote, which could explain the trend away from Obama there.
Kerry didn't exactly do good with the white vote in Louisiana either, quite simply Obama being black had a lot to do with it.
