The main advantage of federalism is more fundamental than the “laboratories of democracy” idea. Federalism is simply the best political system ever conceived of for maximizing human happiness. A one-size-fits-all policy imposed at the national level has the potential to make very large numbers of citizens unhappy, even if it was arrived at democratically. In a pure democracy, I always say, 51 percent of the people can vote to pee in the cornflakes of 49 percent of the people.