This article on transportation spending illustrates the fundamental problem with government spending: spending is based on political considerations and not on anything that might resemble good sense. Unless something very unusual happens, government spending is usually unwise.
Consider the "cap and trade" bill lurching through Congress. As the WSJ point out, it does almost nothing to reduce carbon emissions while showering vast amounts of money on favored constituencies. Regardless of your view of "global waming" and our ability to change it, it’s clear that nothing effective is being done other than to create future campaign contributions and generate a lot of "feel good" PR.
The blogosphere is full of people debating policy. What’s clear is that whatever policy is chosen, our government has almost no ability to carry it out in a sensible way. To me, that’s the bigger issue.