In 1974, the Supreme Court decided the case of United States v. Nixon, popularly known as the “Nixon Tapes” case. The question before the Court was whether President Nixon could defy a subpoena, obtained by the Special Prosecutor in the federal conspiracy trial of Attorney General John Mitchell and six other members of the Nixon White House, directing the President to turn over the secret White House tapes.

The legal issue had two important parts. One was whether the Court even had the power to rule on the matter. The other was whether, if the Court had such power, it should nonetheless defer to the President on the basis of “executive privilege.”

Popular understanding of the case is that the Court ordered Nixon to turn over the tapes, and that ruling led to his resignation a few weeks later. That much is accurate as far as it goes, but the actual opinion is more than just an order in favor of the Special Prosecutor. And the specifics of the case are important for our times.

First the question of “justiciability.” Nixon argued that under the separation of powers doctrine, the Court had no right telling him what he could and could not do. According to his lawyers, conversations within the executive branch of government were entirely outside the Court’s power.

The Court disagreed. Reiterating the words of Chief Justice Marshall in his 1803 opinion in Marbury v. Madison, Chief Justice Burger, himself a Nixon appointee, wrote, “It is emphatically the province and duty of the judicial department to say what the law is.”

Having decided that it had to power to decide the case, the Court then confronted the harder question. How should it rule on the merits? Nixon argued that in order to do his job as president, he needed the freedom to talk candidly with his advisers without fear of public disclosure. In other words, he relied on an absolute “executive privilege.”

This was a “matter of first impression,” meaning that no previous Supreme Court case had addressed this question. In his opinion for a unanimous court (Justice Rehnquist, having worked in the Nixon White House, disqualified himself), Chief Justice Burger agreed that such a constitutional privilege does exist, even though it nowhere appears explicitly in the Constitution, but it is presumptive, not absolute. “It cannot prevail over the fundamental demands of due process of law in the fair administration of criminal justice.” The net result was that the Special Prosecutor got the tapes, and Nixon resigned.

Brett Kavanaugh, President Trump’s Supreme Court nominee, will face questions from senators after the summer recess. I’ll bet someone will ask about comments he made in 1999, speculating that “Maybe Nixon was wrongly decided … heresy though it is to say so. Maybe the tension of the time led to an erroneous decision.” He went on to call it a “huge step” for the Court to order a President to disclose information.

Later statements by Kavanaugh suggest that he may have retreated somewhat from his skeptical view of the Nixon Tapes case, but we may not find out during the confirmation hearings. After all, nominees have become adept at refusing to answer questions about legal questions on the grounds that they may someday be called up to rule on the subject.

And that is the problem. According to the Constitution, the presidential power to appoint “Judges of the Supreme Court” is subject to the “advice and consent” of the Senate. How, it’s fair to ask, can a senator cast an informed vote if all he or she knows is that the nominee believes in the Constitution and in giving due weight to prior decisions?

The answer, in these times, is that it doesn’t seem to matter. With rare exceptions, the “advice and consent” clause has become meaningless. If you’re a member of the President’s party, you vote with him; if you’re not, you vote against him.

How times have changed. Justice Scalia was confirmed by a vote of 98-0, and Justice Ginsberg by 96 to 3.

Trump campaigned on the promise that his nominees would vote to repeal Roe v. Wade, but he never mentioned the Nixon Tapes case, or the concept that not even the President is above the law. We don’t yet have a “Trump Tapes” case, but the FBI obtained a warrant and took possession of taped recordings of conversations between Trump and his former attorney, Michael Cohen.

Will we see the day when Donald Trump seeks to prevent a prosecutor from using those tapes in a legal proceeding? If the question reaches the Supreme Court, will Justice Kavanaugh and his conservative colleagues re-affirm the decision in U.S. v. Nixon?

Or will they turn back the clock and decide that Nixon was right when he said, “When the President does it, that means that it is not illegal.”