I believe we are all indebted to Mr. Bush. Why, you ask? By conrolling all three branches of government, the implementation of conservative policies, and its implications for America, has actually exposed its failings. Granted, those of us on the left hand side of the dial already knew this to be true, but the Kool-Aid drinkers couldn't grasp this fact.
Here's why. For example, whenever Clinton proposed sound economic policy, such as taxing the wealthy and multi-national corporations, the positive effects were co-opted by the Republicans who would say that it was their welfare-cutting that resulted in the positive effects. During mixed government, the Republicans could frame debate as one where their policies were beneficial ones and the progressive policies weren't.
The last six years have shown America that the conservative policies actually were the failed policies and without the Clinton scapegoat they became Emporers with no clothes.