Do constitutional unamendability rules make a difference?

Abstract Leaders often try to amend constitutions to remove checks on their powers. To help protect against such democratic erosion, constitutional drafters and jurists sometimes restrict constitutional amendments by: (1) specifying in the constitutional text that certain clauses or principles can never be changed (“Eternity Clauses”); (2) granting apex courts the power to review the procedural validity of amendment processes (“Amendment Review”); or (3) developing judicial doctrines that block amendments that change the constitution’s nature (“Unamendability Doctrines”). But are unamendability rules actually associated with differences in countries’ levels of democracy? We argue that Eternity Clauses are likely to emerge in conditions more conducive to protecting democracy, while court-created doctrines will emerge in conditions when democracy is under threat. We also hypothesize that enforcement is difficult because when would-be autocrats command enough political power to amend their constitution, it is hard for both courts and political actors to resist. We test this argument using data on countries’ unamendability rules and their levels of democracy. Across three research designs—cross-country comparisons, panel regressions, and event studies—we find some evidence that countries that adopt Eternity Clauses subsequently have higher levels of democracy, but this may be due to differences in countries’ democratization trends prior to adopting them. In contrast, we find little evidence that Amendment Review or Unamendability Doctrines are associated with differences in democracy levels. We do find that unamendability rules are associated with higher levels of constitutional replacement, suggesting that when amendments are not possible, undemocratic reforms might be pursued by writing a constitution from scratch. We supplement these quantitative findings with a case study of presidential term limit evasion, which shows that unamendability rules are rarely invoked to halt term limit amendments.