Don Boudreaux writes a book review in the WSJ that includes this bit of reasoning that I always find compelling in use against big government advocates:
In this worldview, people’s weak wills and eccentricities make them prey both to shameless hucksters and to their own strange psychological traits. Ironically, however, Mr. Sunstein fails to explain why the irrational and impulsively childlike people who are apparently the nation’s citizens will elect a government that is itself not irrational and impulsive—or why government officials won’t exploit, for their own corrupt ends, the people’s cognitive weaknesses.
If you think, in general, that people make bad decisions, why in the world do you want a government that is essentially directly elected by the people AND VERY VERY BIG? If you think people make bad decisions, it would seem that the solution to government would be a very Constitutionally limited government in which those who were politicians (elected, appointed, or however they got their jobs) could do very little to impact the lives of others. Senator Ivy advocates for just such a government in Evolve, Part 2: Incentives.