Last week, the Supreme Court of the United States announced that it would bar most forms of protest on the marble plaza in front of the court, as well as other surrounding areas on the court’s grounds, in part to protect “the appearance of the court as a body not swayed by external influence.” The Supreme Court now bans

demonstrations, picketing, speechmaking, marching, holding vigils or religious services and all other like forms of conduct that involve communication or expression of views or grievances, engaged in by one or more persons, the conduct of which is reasonably likely to draw a crowd or onlookers.

The judiciary must not be—or even appear to be—partial to any person or sympathetic to any cause because, as Justice Joseph Story stated in his Commentaries on the Constitution, the judiciary “must possess wisdom, learning, integrity, independence, and firmness.”

While the new ban might indeed help preserve the idea that the court’s decision making should not be affected by outside influences—the best way to accomplish this goal is for judges to refrain from engaging in judicial activism. From playing favorites by elevating obvious sympathy for criminal defendants above the law to importing foreign law to interpret the U.S. Constitution, judicial activism comes in many forms. But from state courts to the U.S. Supreme Court, judges have a duty to interpret and apply laws and the Constitution neutrally and without personal bias. This is essential to the rule of law and to the Constitution’s structural limits on government.

While the term “judicial activism” is often the battle cry of those simply upset by the outcome of a certain decision, there are objective criteria by which judicial activism can be judged.  Elizabeth Slattery writes in a new Heritage Legal Memorandum that a “simple working definition is that judicial activism occurs when judges fail to apply the Constitution or laws impartially according to their original public meaning, regardless of the outcome…”

Judicial activism is not a criticism of the result of a case, but of the way in which the judge reached that decision, and it can occur when a judge upholds an unconstitutional law or strikes down a lawful one. “Labeling as ‘activist’ a decision that fails to meet this standard,” Slattery says, “expresses disagreement with the judge’s conception of his role in our constitutional system, not policy disagreement with the outcome.”

While there are many historical examples of judges engaging in judicial activism (many catalogued here), it is certainly not a thing of the past. Three recent examples demonstrate the many dangers of judicial activism. From the Montana Supreme Court contorting the text of a statute and trampling the “free exercise” rights of a religious group to the Sixth Circuit Court of Appeals playing legislator with respect to federal drug-sentencing policy, judges continue to abandon their constitutional role.

Judges must put the requirements of the law above their policy preferences. When they fail do so, they trade the stable rule of law for the fickle rule of men.

Read more about how to spot judicial activism here.