In recent years, the justices of the Supreme Court have ruled definitively on such issues as abortion, school prayer, and military tribunals in the war on terror. They decided one of American history's most contested presidential elections. Yet for all their power, the justices never face election, and hold their offices for life. This combination of influence and apparent unaccountability has led many to complain that there is something illegitimate--even undemocratic--about judicial authority.

In The Will of the People, Barry Friedman challenges that claim by showing that...