The Supreme Court has agreed to hear one of the most important tax cases in history, which could either greenlight the constitutionality of an economically disastrous wealth tax, or destroy critical parts of the U.S. tax system. Unless the justices take a middle road and define the 16th Amendment according to the history and traditions of the U.S. tax system, the case will result in bad law and worse outcomes. The case (Moore v. United States) concerns the constitutionality of the 2017 Tax Cut and Jobs Act (TCJA). The act imposed a mandatory repatriation tax on pre-2018 profits that companies...