Given the complexity of the law and the complexity involved in saying what really happened in a given dispute, all judges, and especially those on the Supreme Court, often have to exercise a quasi-legislative power: They have to decide what should be done based on their own moral and political values, since existing legal standards conflict, or are indeterminate, or are silent on the problems they confront. The Supreme Court, as the final court of appeal in our system, is the super-legislature of last resort. And that is why Republicans blocked Garland’s nomination and why Trump chose Gorsuch. Republicans expected Garland to vote against their objectives on the super-legislature. Trump expects Gorsuch to vote with the Republicans.

None of this is controversial among insiders. Judge Richard Posner of the U.S. Court of Appeals for the 7th Circuit — nominated by President Ronald Reagan — made these points less than a decade ago in his book “How Judges Think,” while Benjamin Cardozo — nominated to the Supreme Court by President Herbert Hoover — delivered the same lessons in “The Nature of the Judicial Process” nearly a century ago. All jurists know that good judging demands not simply technocratic expertise but moral and political judgment of the kind exercised by a conscientious legislator.

Supreme Court nominations are controversial because the court is a super-legislature, and because its moral and political judgments are controversial. As a super-legislature, it has limited jurisdiction, depending on what cases are brought before it, but those cases are important enough. Just as no one would expect Republicans or Democrats to assent to appointments to the Senate without regard to political ideology, it is naive to expect anything similar in the case of nominations to the Supreme Court.