28 RUCHO v. COMMON CAUSE Opinion of the Court is easy to imagine how different criteria could move the median map toward different partisan distributions. As a result, the same map could be constitutional or not depending solely on what the mapmakers said they set out to do. That possibility illustrates that the dissent’s proposed constitutional test is indeterminate and arbitrary. Even if we were to accept the dissent’s proposed baseline, it would return us to “the original unanswerable question (How much political motivation and effect is too much?).” Vieth, 541 U. S., at 296–297 (plurality opinion). Would twenty percent away from the median map be okay? Forty percent? Sixty percent? Why or why not? (We appreciate that the dissent finds all the unanswerable questions annoying, see post, at 22, but it seems a useful way to make the point.) The dissent’s answer says it all: “This much is too much.” Post, at 25–26. That is not even trying to articulate a standard or rule. The dissent argues that there are other instances in law where matters of degree are left to the courts. See post, at 27. True enough. But those instances typically involve constitutional or statutory provisions or common law confining and guiding the exercise of judicial discretion. For example, the dissent cites the need to determine “substantial anticompetitive effect[s]” in antitrust law. Post, at 27 (citing Ohio v. American Express Co., 585 U. S. ___ (2018)). That language, however, grew out of the Sherman Act, understood from the beginning to have its “origin in the common law” and to be “familiar in the law of this country prior to and at the time of the adoption of the [A]ct.” Standard Oil Co. of N. J. v. United States, 221 U. S. 1, 51 (1911). Judges began with a significant body of law about what constituted a legal violation. In other cases, the pertinent statutory terms draw meaning from related provisions or statutory context. Here, on the other hand, the Constitution provides no basis whatever to guide the exercise of judicial discretion. Common experi-