The class action has come of age in America. With increasing regularity, class litigation plays a central role in discussions about theory, doctrine, and policy in the American civil justice system. The dynamics of the class action lie at the heart of current debates over the nature of the litigation process and the limits of adjudication in effectuating social policy. Choice of law analysis has enjoyed a renaissance as its significance to the question of class certification has become apparent. Class litigation now frequently drives debates over tort reform and the phenomenon of regulation through litigation. In these and many other respects, we have entered a new dispensation: the era of the nationwide class action. The passage of the Class Action Fairness Act of 2005 (CAFA) —the first occasion on which Congress has enacted a generally applicable legislative policy pertaining to aggregate representative litigation —aptly punctuates that arrival.