The literature has pointed out the negative aspects of political dynasties. But can political dynasties help prevent autocratic reversals? We argue that political dynasties differ according to their ideological origin and that those whose founder was a defender of democratic ideals, for simplicity labeled “pro-democratic dynasties,” show stronger support for democracy. We analyze the vote by the French parliament on 10 July 1940 of an enabling act that granted full power to Marshall Philippe Pétain, thereby ending the Third French Republic and aligning France with Nazi Germany. Using data collected from the biographies of parliamentarians and information on their voting behavior, we find that members of a pro-democratic dynasty were 9.6 to 15.1 percentage points more likely to oppose the act than other parliamentarians. We report evidence that socialization inside and outside parliament shaped the vote of parliamentarians.