It is hardly news to observe that a proposed legal reform is not adopted even though nearly all experts believe it would effectively advance the law’s widely supported policy goals. But if this phenomenon is commonplace, that is all the more reason for trying to understand why it happens. The recent effort to reform Arizona’s child support guidelines provides a particularly compelling case study of such a failed law reform effort, for several reasons. First, child support has generally not been politically contentious: Both Democrats and Republicans have for several decades combined to support changes in child support law intended to ensure that non-custodial parents contribute to the support of their children. Second, this is not merely a case of legislative inaction. In Arizona, as in many states, the state supreme court is the body assigned the task of writing the rules that establish how much child support a non-custodial parent must pay. The proposed reform would have become law had the legislature not affirmatively acted to overrule the recommendations of a series of committees the court had appointed to study the issue. Finally, all available information suggests that the proposed reforms were more consistent with the views of the Arizona electorate than the existing provisions they would have replaced. In sum, the legislature acted to prevent adoption of child support reforms proposed by the public bodies entrusted with deciding them even though the reforms were consistent with the views of the public and supported by nearly all the experts asked to study them. This Article attempts to understand why this happened. Among other things, it concludes that the reform suffered from an asymmetry in citizens’ motivation to engage the political process: those who stand to gain from a reform may not work as hard for its adoption as those who stand to lose from it will work for its defeat.