A very insightful essay from Reason magazine. The concluding paragraph:

We often focus on the size of government, as measured in percentage of GDP taxed and spent by the government, which is an important and measurable concept. But our real concern is power. What kind of power does the government wield over the people? Powerful state institutions tend to be large, but that doesn't mean that a larger state is necessarily exercising more power. Imagine a small town that adds two officers to its police force. Now it has more police officers, and that costs more money; the government is "larger." But if the officers now do a better job of arresting violent criminals and protecting the lives and property of the people--and refrain from arresting or hassling non-criminals--then the government has not expanded its power. Indeed, better eight officers protecting lives and property than six officers enforcing drug laws and blue laws. We should focus on what is actually important--the exercise of arbitrary power over others. And in that regard slavery and conscription, among other things that marred parts of our American past, loom very large.

via Up from Slavery - Reason Magazine.