With three independent branches, a legislature divided into two houses, and many diverse constituencies, it is remarkable that the federal government does not collapse in permanent deadlock. Yet, this system of government has functioned for well over two centuries, even through such heated partisan conflicts as the national health-care showdown and Supreme Court nominations. In Partisan Balance, noted political scholar David Mayhew examines the unique electoral foundations of the presidency, Senate, and House of Representatives in order to provide a fresh understanding for the...