the GOP knows that the middle DOES matter. They know that by playing to their base in very well-crafted ways, they can shift the very definition of what the middle is. By introducing radicalism into the public discourse (and taking initial heat for it), whatever used to be radical within this context becomes moderate by comparison.

Systematically, piece by piece, the GOP takes what had been considered impossibly radical positions and makes them worthy of consideration just by talking about them--and then makes what had been considered outside possibilities truly possible. Now, ....

But the important thing to remember is that the Republicans are carrying out this same exercise with every public policy debate today--from invading Iran to making birth control illegal to eliminating Social Security. The once unthinkable becomes possible--and they don't care if they take some heat for it initially.