The Supreme Court's latest scandals boil down to a question as old as the Romans: 'Who will guard the guardians?'

• Supreme Court justices are under renewed scrutiny due to recently uncovered financial dealings.
• Revelations about Justices Clarence Thomas, Neil Gorsuch, and John Roberts highlight the lack of ethics enforcement.

Supreme Court justices and America's top political brass are struggling to tackle a baseline ethics question that the Romans grappled with millennia ago.

"There's a really practical issue of, 'Who will guard the guardians?' That's a question that the Romans asked over 2,000 years ago," Doron Kalir, a professor at Cleveland-Marshall College of Law and an expert in legal ethics, told Insider.

In recent weeks, experts have raised questions about how effective the court can be in policing itself, after the longest-serving justice, Clarence Thomas, was discovered to have sold his childhood home to GOP mega-donor Harlan Crow, as well as indulged in lavish trips on Crow's dime — without disclosing any of it. Thomas also did not recuse himself from a 2004 appeals case that involved a company connected to Crow's real estate empire, per Bloomberg. Thomas has denied wrongdoing or a conflict of interest and said he was told that he didn't need to report the trips.

Last week, reports emerged that Justice Neil Gorsuch sold property to the head of a major law firm shortly after his confirmation, without identifying the buyer on his federal disclosure forms. And on Friday Insider's Mattathias Schwartz reported about a whistleblower alleging that Justice John Roberts' wife was paid $10 million by elite law firms, including one who argued a case in front of Roberts at the court.

Roberts last week also declined to have justices sit for an ethics hearing requested by members of the Senate Judiciary Committee, after initial revelations into Thomas' and Crow's long-standing relationship.

The Supreme Court did not return Insider's request for comment.

As questions have stacked about how the justices — who can play by their own rules and whose dealings can be shrouded in secrecy — could be policed on these issues, answers have become harder to pluck.

Steve Vladeck, a professor at the University of Texas School of Law and author of the forthcoming book "The Shadow Docket: How the Supreme Court Uses Stealth Rulings to Amass Power and Undermine the Republic," previously told Insider that ethics enforcement should be a nonpartisan issue that is in the interest of the court.

"The reason why we have ethics rules and financial disclosure requirements is not just to ensure that the justices are recusing from the right cases," Vladeck told Insider, "It's also because of broader questions about the potential for undue influence."

Ethics enforcement is not partisan politics

Vladeck said that in Thomas' 2004 case, it appears that he should have recused himself. But the bigger issue than whether his decision not to recuse himself was in good or bad faith, is that the people who are able to enforce ethics rules for the justices are the justices themselves.

"But part of what we get into here is also that it's not that the rules are a mess; it's that they have no enforcement mechanism," Vladeck said. "So, even when justices really have a fairly clear obligation to recuse, they are their own masters."

Technically, the Supreme Court and lower federal courts are bound by 28 USC section 455, a legal mechanism for recusals tied to the presence of family members or potential financial benefit. But parties arguing before the Supreme Court cannot challenge justices for a lack of recusal like people can in lower courts.

"This is not partisan, this is institutional," Vladeck said. "And what that drowns out is that the real problem here is not conservatives or progressives. The real problem here is that the court as an institution has no effective way of policing itself."

The Supreme Court is the only court not bound by a specific code of ethics, but all federal judges, including the top justices, are expected to follow ethics statutes and are required to file financial disclosure forms. In a rare instance in 1969, a SCOTUS justice resigned after a purported ethics scandal.

There is an official Code of Conduct for Federal Judges, but it applies to all federal judges except the Supreme Court justices, simply because that's what the Supreme Court decided, according to Kalir. For instance, Chief Justice Roberts wrote in a 2011 report that he did not think the Constitution granted Congress the power to impose a code of conduct on the Supreme Court.

Still, Kalir said the justices should at least try to comply with the code, which includes avoiding the appearance of impropriety, even if it does not technically apply to them.

As it stands, Congress is unlikely to try to pass a new enforcement mechanism for the court.

Currently, justices are also not likely to face any hard inquiries or even impeachment and removal from a heavily partisan Congress; the House is controlled by the GOP, which has no incentive to impeach a conservative judge. In the Senate, Democrats have called for oversight and investigations, but even if a justice was impeached in the House, the majority is so slim in the Senate that it may be hard to reach a two-thirds majority to convict and remove someone from their post.

The current scandals have ignited a debate across the political aisle as to what violates those rules, with GOP lawmakers defending Justice Thomas.

"We may all disagree about the exact content of those rules, we may disagree about which actions do and do not violate those rules," Vladeck told Insider. "But it seems like we ought to be able to agree that if we're going to have rules, it would be kind of pointless if there was no way of enforcing them."

What's pretty simple is how a lack of enforcement mechanisms led us here.

"That's what the Supreme Court decided, and they're supreme," Kalir told Insider.