THE presidential election of 2000 presented the United States and the world with a vivid lesson in the power of political partisanship and its potentially damaging effects. Through five long weeks of angry confrontations in the legislature, the courts, the media, and the streets, partisans on both sides disputed a whole series of issues related to the counting of the votes. Not only Republican and Democratic officials but also judges, columnists, academics, and ordinary Americans repeatedly sided with the positions taken by their favored presidential candidate. All claimed to be guided by the public interest, the law, or the principles of justice, yet on every point at issue, no matter how narrow or technical, they almost invariably espoused the view that favored their own party. Virtually no one publicly broke ranks on any matter. The division between the two sides could hardly have been more systematic or more pronounced.