Why are blue (Democratic) states turning red (Republican)?

Why are blue (Democratic) states turning red (Republican)?  Interesting discussion from the perspective of a liberal.  The lead:

It is one of the central political puzzles of our time: Parts of the country that depend on the safety-net programs supported by Democrats are increasingly voting for Republicans who favor shredding that net.

The central conclusion of the writer (Alec MacGillis) is that the problem (from the Democrat's perspective) is different than it appears at first blush.  It's not that the welfare recipients are voting Republican against their own self-interest.  It's that they're not voting at all.

For me the most interesting bit in here was the frank admission of the dependency of the progressives (Democrats) on the essentially purchased vote of the welfare recipient.  It's also interesting, as always, to see the chain of thought of a dedicated progressive...