How could a country founded on the ideal of individual liberty, with a state devoted to the mission of protecting it, slide down the road to tyranny as fast as, and sometimes faster than, other countries? [Public Choice theory] suggests some explanations. With hindsight, the Founders probably did not take seriously enough the danger of the state, as illustrated in Madison’s argument for a federal government that would be kept in check by the States and the will of the citizens. Perhaps the state is so dangerous that trusting it with any glorious mission is looking for trouble, even if this mission is the protection of liberty.
Based on my reading of Howe's What Hath God Wrought, I would suggest that the growth of government was probably inevitable. The Reform impulse was there from the very beginning, and the opposing limited-government impulse was heavily entangled with slavery, which put it on the wrong side of history.
During the 1815-1848 period that Howe chronicles, the Reform impulse stayed mostly outside of government. In a rural, religious society, the Revival was for reformers a more effective tool than government. Howe points out that political conventions began as imitations of Revival meetings, an origin that will be easy to appreciate when we observe the conventions in the coming months.
The way I look at it, the takeover of government by the Reform impulse took place in a series of lurches. The Civil War, which broke the power of the South and states' rights, was one such lurch. The two World Wars also were lurches. Although there was some retrenchment after each of those three wars, their general effect was to set precedents for government expansion. As libertarians are wont to say, war is the health of the state.
Two other lurches took place as result of political landslides. Franklin Roosevelt in the 1930's and Lyndon Johnson in 1964-65 moved the country in the Reform direction. Perhaps an Obama landslide would to something similar, although I have doubts.
I believe that until the late 1960's, centralization and concentration of power were the trend in media, business, and government. In business, and especially in media, that trend has reversed over the past forty years. But concentration of government power has continued to increase. I believe that this is an anomaly, and that at some point the contradiction between the technology trend and the government trend will assert itself. Just as we are seeing sharp declines in the proportion of people who read newspapers and watch network television, I expect to see less support for centralized government. That is my vague, technology-based libertarian hope.