From campus protests to the Congress floor, the central feature of contemporary American politics is ideological polarization. In this concise, readable, but comprehensive text, Steven E. Schier and Todd E. Eberly introduce students to this contentious subject through an in-depth look at the ideological foundations of the contemporary American political machine of parties, politicians, the media, and the public. Beginning with a redefinition of contemporary liberalism and conservatism, the authors develop a comprehensive examination of ideology in all branches of American national and state governments. Investigations into ideologies reveal a seeming paradox of a representative political system defined by ever growing divisions and a public that continues to describe itself as politically moderate. The work's breadth makes it a good candidate for a course introducing American politics, while its institutional focus makes it suitable for adoption in more advanced courses on Congress, the Presidency, the courts or political parties.