There's are studies to suggest that government is just as efficient as the private sector. I have neither the citations nor inclination to defend this however.

As correctly pointed out, supply-side/Keynesian economics are not a zero-sum game. I find it disheartening that the corporate tax rate, which is highest in the western world, has been completely absent from the debate. Perhaps if the tax rates of hedge-funders and unemployed billionaires were funneled into the engine of the American economy, we'd see better returns.

The GOP's identity crisis seems to be a natural part of the political cycle. Democrats had the same problem after Kerry/during Obama's primary. The GOP does stand for something, but that seems to be at odds with what the public wants. The likely result, however, will be a refinement, not a change of message for the GOP; just as it was for the Democrats.