Wise words from Ezra Klein about how we should worry about deficits and long term spending:

[T]he reason to worry about the deficit today — and, more to the point, the trends in government spending and taxation that drive it — is that the most worthwhile kinds of government spending are getting crowded out.

The key insight behind this theory is that some forms of government spending rise automatically and rapidly, and are very politically difficult to cut, while other forms of government spending need congressional approval every single year and have few constituencies to protect them. In the first category are Medicare and Medicaid and Social Security, all of which are projected to consume much more of the federal budget in the coming years. In the second category are things like education funding, research and development, stimulus, infrastructure investment, and even the military. And the fear is the first category is squeezing out the second category.