On the spending side, the main point is that we should not be considering massive public-works programs that do not pass muster from the perspective of cost-benefit analysis. Just as in the 1980s, when extreme supply-side views on tax cuts were unjustified, it is wrong now to think that added government spending is free.
That's from Robert Barro's essay in the WSJ noting that stimulus spending will not magically multiply through the economy. He walk through the economics very nicely.
This doesn't mean all spending is bad (and I'm a particular fan of public goods investment in a smart grid). But it does mean we need to have a much more serious talk about the deficit than we are having. If you care about the next generation, that is. Can you imagine the White House submitting a budget with a 1.7 trillion dollar surplus? It's scary to think the gap between government revenues and spending will exceed 10 percent of what the private economy produces. Just the deficit!