In light of the Supreme Court’s unwillingness to adopt an ethics code for itself, Congress must step in and pass a statute imposing standards. All other judges in the country — state and federal — are bound by ethical rules. It is inexcusable that the most important and powerful judges are not.

The issue has taken on urgency after a recent investigation by ProPublica revealed that Justice Clarence Thomas has over the years accepted lavish trips and other gifts from a major Republican donor. Similar calls for ethics rules followed a report last fall in The New York Times of allegations that a landmark 2014 contraception decision “was prematurely disclosed through a secretive influence campaign by anti-abortion activists.”

Chief Justice John Roberts, who has questioned whether Congress even could impose an ethics code on the court, said last month that he and his colleagues were continuing to take steps to address questions about the justices’ ethical standards. But he offered no details.

Congress should not wait on the court any longer. It has the authority to hold justices to a code of conduct. If it fails to do so, it will share responsibility for the ethics mess at the Supreme Court.

One argument against Congress stepping in is that it would violate the separation of powers for legislators to impose standards on a coequal branch of government. The chief justice made a cryptic reference to this last month, saying he was “confident that there are ways” to ensure that justices adhere to the highest standards that are “consistent with our status as an independent branch of government and the Constitution’s separation of powers.”

But separation of powers does not mean that one branch of government operates entirely independent of the others. Congress, for example, regulates many aspects of the Supreme Court, including its size, the salary of the justices and its budget. Congress has also long imposed financial reporting requirements on the justices and limits on the gifts and outside income they can receive, though as the chief justice noted in 2011, “The court has never addressed whether Congress may impose those requirements on the Supreme Court.”

For example, a federal law, 28 U.S.C. § 455, requires federal judges, including justices, to disqualify themselves in any proceeding in which their “impartiality might reasonably be questioned.” Also, the Ethics in Government Act of 1978 requires government officials, including justices, to disclose many kinds of financial interests and transactions. The statute also applies to the president. It is hard to imagine the court ruling that all of these laws are unconstitutional.

The chief justice has also raised concerns about recusal in cases in which a justice’s impartiality might be reasonably questioned. He has noted that in the case of the Supreme Court, recusal by a justice would force the court to decide the case in question without its full complement of justices — unlike in lower courts, where a judge who steps aside can be replaced by another judge.

This argument is specious. A recent analysis by Bloomberg Law found that the justices recused themselves in roughly 3 percent of appeals since 2018, with Justices Samuel Alito and Elena Kagan doing so most often. The court managed in these circumstances. The court also operates short-handed when there is a vacancy, as it did for over a year after Justice Antonin Scalia died in February 2016, until Neil Gorsuch was confirmed in April 2017.

Even if, with the advent of an ethics code, there might be more instances in which a justice might recuse, it would be worth it to ensure that justices abide by the same rules as all other judges.

A further objection is that imposing ethical standards on justices is partisan. Last month, when the Senate Judiciary Committee held a hearing on whether to impose an ethics code on the court, some of the Republican senators on the committee decried the effort as political. That is nonsense, because all justices — regardless of who appointed them or their ideology — would be bound by the same rules.

Liberals and conservatives should want a Supreme Court that is above reproach. The hope is that there will be enough members of Congress of both parties who are willing to stand up for ethics, especially when such standards don’t even apply to them.

Senators Sheldon Whitehouse and Richard Blumenthal, along with other Democrats, have introduced the Supreme Court Ethics, Recusal and Transparency Act. Among other things, it would require the Supreme Court to adopt a code of conduct within 180 days of the bill’s enactment. It also would create a transparent process for the public to submit ethics complaints against justices, to be reviewed by a random panel of chief judges. And it would mandate rules requiring disclosure rules for gifts, travel and income received by justices and law clerks that are at least as rigorous as the House and Senate disclosure rules.

The hard question is how the ethical rules should be enforced. Now it is left to justices to decide whether to recuse themselves from cases. Allowing people to judge their own situations never can inspire confidence in the decisions. Alternatives have been suggested, including having a panel of retired appeals court judges review these questions or referring the matter to the other justices.

The public’s view of the court is plummeting. A recent survey by Quinnipiac University found that more registered voters disapprove of the job the court is doing than at any other point in the past 20 years. Forty-six percent of Americans thought Justice Thomas should resign after the recent revelations by ProPublica.

The case for the Code of Conduct for federal judges is made succinctly in its first sentence: “An independent and honorable judiciary is indispensable to justice in our society.” That should apply equally to the nation’s highest court.

Erwin Chemerinsky is the dean of the School of Law at the University of California, Berkeley.