The second excellent reason to shrink the Court is that it would reduce the Court’s capacity to do damage to the Constitution. How would that work? Simple: A smaller court means diminished judicial activism. As the Court’s size shrinks, activist majorities become mathematically harder to put together. Four votes out of seven is harder to achieve than five of nine. Four out of six becomes harder yet. With a Court of six, major changes in interpretation of the Constitution and federal laws would require a two-thirds majority rather than a 5-to-4 squeaker — the margins by which the Court upheld Obamacare, created a right to same-sex marriage, and reaffirmed Roe v. Wade. As at present, ties would yield no precedent but merely affirm lower courts’ rulings, with more limited effect. Fewer justices thus means less judicial activism, at least at the Supreme Court level.

The membership-attrition, activism-reduction effect has already occurred to a limited extent with eight justices on the Court instead of nine following the death of Justice Scalia in February. The last Supreme Court term saw several major cases decided extremely narrowly — and some essentially not decided at all — rather than produce ties. This left some legal disputes to be worked out in different ways, which is all to the good. The eight-member Court kicked a few constitutional cans down the road, and the nation is no worse for it. Other tie votes left lower courts’ decisions standing, avoiding 5–4 national “landmark” decisions of doubtful correctness and durability that would have provided flash points for ongoing wars over control of the Court. Law professors and activists may bemoan this result. Let them moan: A lower court precedent does less harm than a nationwide one.

Even where the Court engaged in shameless judicial activism last term (as in the Texas abortion-clinic regulation case and the Texas race-preferential college-admissions case), it took a five-vote majority out of eight, rather than nine. (In those cases, Justice Scalia’s vote would not have made any difference.) Usually, that is a harder majority to achieve. And as noted, attrition makes activist majorities increasingly harder to forge. The situation only improves as the Court dips from eight robes to seven to six. And right now, the three oldest Justices — Ruth Bader Ginsburg (83), Anthony Kennedy (80), Stephen Breyer (78) — are all judicial activists, of various stripes, meaning that attrition is likely to lead to a less leftist Court.