I propose to defend and explore three claims in this Essay. First, there is very little actual “law” in federal constitutional law in the United States, especially with respect to cases that end up at the Supreme Court. There, the Court operates as a kind of super-legislature, albeit one with limited jurisdiction. The jurisdiction is limited in two important ways: first, the Court can only pass on issues that are brought before it; and second, the Court is constrained, to some extent, by its past decisions and by constitutional and legislative texts. The problem, however, is that those constraints underdetermine the Court’s decisions in most cases, so the Court essentially makes its final choice among the legally viable options based on the moral and political values of the Justices, and not simply on the basis of legally binding standards…

“Constitutional Law, Moral Judgment, and the Supreme Court as Super-Leg” by Brian Leiter (emphasis added)

That’s academese for the litigator’s commonplace: “if the case were easy, it wouldn’t have made it to the Supreme Court.”

But Justices serve, effectively, for life, and are not beholden to the President who appointed them. So while their opinions are underdetermined by external constraints, they’re not crassly political in the way far too much commentary implies.