As Justice Breyer has observed, "[j]udges in different countries increasingly apply somewhat similar legal phrases to somewhat similar circumstances." This article explains why constitutional law is bound to display strong underlying similarities, if not signs of convergence, across subnational and national borders. The explanation is threefold. First, constitutional courts experience a common theoretical need to justify countermajoritarian judicial review. This concern, and the stock responses that courts have developed, amount to a body of generic constitutional theory. Second, for heuristic reasons, courts employ common problem-solving skills in constitutional cases, which together constitute a kind of generic constitutional analysis. Third, courts face overlapping influences, largely not of their own making, that encourage the adoption of similar legal rules. These similarities make up a body of generic constitutional doctrine. In conclusion, the article discusses how constitutional pedagogy should be reformed to take account of these developments, and whether judges can or should resist the advent of generic constitutional law.