The interesting question is why Court-packing has been proposed and is receiving media coverage now, before the conservative and constitutionalist majority on the Court has done anything to arouse anger on the Left. The answer is that the plan’s current sponsors have another objective in view — a chance to influence the vote of Chief Justice John Roberts on a decision in Gundy that will revive the nondelegation doctrine.

In two cases arising under Obamacare, Roberts showed that he is reluctant to have the Court take controversial positions on major public issues. In both cases, he sided with the four liberals on the Court, upholding the law against strong conservative challenges. Now, apparently, the sponsors of the new Court-packing plan hope that this threat will again persuade the chief justice to lead the Court away from another major confrontation.

Is this strategy likely to succeed? There is good reason for doubt. Chief Justice Roberts is a constitutionalist, like four of his fellow justices — Thomas, Alito, Gorsuch, and Kavanaugh. For constitutionalists, there is nothing more important than protecting, and if necessary restoring, the separation of powers as the central structural element of the Constitution.