The clause says that “no person holding any office of profit or trust” shall “accept of any present, emolument, office or title, of any kind whatever, from any king, prince or foreign state” unless Congress consents. The word emolument means compensation for labor or services.

Asked about the clause by Senator Leahy, Judge Gorsuch said “the Emoluments Clause has sat in a rather dusty corner” and “is not a clause that has attracted a lot of attention until recently.”

But Judge Gorsuch would say no more given what he said was at least potential litigation on the subject. Lawsuits have been filed against President Trump, claiming he has violated the clause.

“I have to be very careful about expressing any views,” Judge Gorsuch said.

Would Gorsuch recuse himself?

Senator Leahy also asked Judge Gorsuch to say whether he would continue on the Supreme Court to recuse himself from cases involving the Colorado billionaire Philip Anschutz, with whom he has various ties. Among those ties: Mr. Anschutz was Judge Gorsuch’s former client and in 2006, he successfully lobbied the Bush White House to appoint Mr. Gorsuch to the appeals court. Mr. Leahy noted that Judge Gorsuch had left the door open to changing his appeals court practice and participating in cases involving Mr. Anschutz’s interests on the Supreme Court.

Judge Gorsuch did not answer directly, saying he would study the law and the practices of his colleagues and the facts before making a decision. But Mr. Leahy pointed out that the law was the same for both appeals court judges and Supreme Court justices, except that justices’ decisions not to recuse themselves cannot be appealed to anyone.

There is scant precedent about how justices have interpreted whether cases involving former clients raise an actual or apparent conflict of interest because few modern justices had extensive backgrounds in private practice. But Justice Clarence Thomas, who worked as in-house counsel for Monsanto from 1977 to 1979, has participated in cases involving that company.

A nominee with little interest in the wisdom of international law.

Judge Gorsuch echoed earlier Republican Supreme Court nominees when he said American courts should not look to foreign and international law in interpreting the Constitution.