I moved here from CO and watched the state go from conservative/republican to a liberal/democrat majority.
The issue is more and more people do not have what it takes to go out in this world and do what ever it takes to become self sufficient. As the economy worsens, the number of people like this increases., as the standard of living decreases, those type of people increase.
Talk to young people today.
Lots of them have simply given up before they even got started. They had visions, taught by the older generations who raised them, of being able to make a great living etc.....All they talk about now is how life isn't fair, I was lied to, all I can find is a min. wage part time job, the older generations screwed up this country and stole my future etc... They want nothing more than to see wealth redistribution and most vote democrat. Around 65% and this generation is as big as the baby boomers.
Also, the younger generation are more diverse and socially liberal, so when republicans rant about conservative social issues, it turns the young away and they will not vote for them even if they like what else they have to say.
If the trend continues, there is no way to stop it as the old die off and the younger generation become a bigger percentage of the vote. They have the numbers. Some say we have already reached the tipping point. I don't think so personally.