What explains the cross-national diffusion of democratic change? A comparative analysis of two waves of such changes in postcommunist Europe and Eurasia from 1988-2005 suggests that three factors are critical. One is an expansion of opportunities for change; another is the appeal of positive precedents, especially when parallels can be drawn between the “sender” and the “receiving” country; and a third is the rise of transnational groups supporting political change. For subversive innovations, all three factors seem to be necessary—which is one reason why each of the waves of democratic change came to an end.