'We often think of the long-term stability in the positions that the parties take on major issues. Changes, when they come, are supposed to be associated with major events, perhaps realignments. And yet, as Karol shows, there is more change than that. Not only that, but, as he shows, there are three different paths, with different dynamics and speeds of adjustment, the latter largely due to the role of 'interest coalitions'. Karol demonstrates his claims through careful study of a number of particular issues, showing, inter alia, that what we think of as left and as right, as Democrat and Republican is a function of parties, leaders, and interests, all of which change over time. And, in this, we learn not only much about American politics but about the limits of our scholarly understandings and the theories that lie behind them.' John Aldrich, Duke University