I agree that it probably doesn't have to do with changing idealogy among the former residents of those states, but I do think it has a lot to do with changing demographics.
As is probably well known, California is a very strong blue state (by and large - although we have had a number of Republican Gov.). However, there have been large numbers of California population moving out of state, primarily to Arizona and Nevada (where the air is cleaner, the land cheaper and fewer people). To as lesser extent, population of New Mexico, Colorado, Utah have grown as a result of flight from California. As a result these once very strong Red states are now becoming a little more dilute. They all are still pretty strong Red states and will likely continue to be so for the near future. But an interesting thing to research for most people who enjoy politics (Red or Blue) is the read some of the studies who have talked about Demo strategies towards the west. The South is pretty much gone for Democrats with the exception of Florida. Its definitely interesting though--- for Republicans, does this mean California may come into play? An interesting thought, probably not for a while in a Presidential election but I hate to play into their strategy---McCain, a nearby strong moderate candidate could carry California...........btw KCC: Thats my crystal ball.....which I am sure you will comment on as well.