If you really want to trample on free speech in America, you must start by enlisting the right sort of people — academics, liberal politicians, editorialists and "good government" groups like Common Cause — on your side. Then you'll be free to write a law that defies the First Amendment, and the courts will solemnly assure the public that what you did is fine. The McCain-Feingold act of 2002 is one such law, but there are plenty of others. If, on the other hand, you fail to attract the right sort of support for your crusade to undermine the Constitution,...