Because the Constitution doesn’t explicitly define the exact approach for the Judicial branch to interpret the law, judicial activism’s definition, as others have said today, on the Arena, depends on which branch of government is applying the term. And its been that way every since Marbury v. Madison. From the executive and legislative branches’ viewpoints, when the judgment is counter to one’s political position, the judge is activist; when the judgment supports one’s political position, the judge is restrained
On the other hand, from the Judicial branch, activism is merely one point on a continuum of approaches to interpreting law. Restraint, then, is simply another point. I must leave it to Arena’s legal experts, which I am not, to define the various many other points on this judicial-interpretive continuum, from originalism to structuralism and beyond, but both activism and restraint are surely connected to an individual judge’s subjective belief about the roles of judges.
Which brings up Chief Justice Roberts’ oft-quoted definition that judges are like umpires: “Judges are like umpires. Umpires don’t make the rules; they apply them.” This statement has always seemed incomplete to me because, as everyone knows, no two umpires have the same strike zone. The strike zone, that is, was different in Dred Scot v. Sandford from what it was in Brown v. Board of Education. There’s a case to be made that Justice Roberts’ umpiring uses a smaller strike zone, if you will, for liberal pitchers and a wider one for conservative ones. Does that mean he’s not applying the law or that he’s sometimes activist and sometimes restrained? Hard to say. But it does mean that the liberal side knows that it has to throw an indisputable strike for Justice Roberts to call it a strike, while conservatives know that the judge is predisposed to calling anything near the plate and positioned below the chin and above the ankles a strike–especially late in the game.