(NewsNation) — Sen. Dick Durbin, D-Illinois, called for the Supreme Court to adopt a code of conduct at a Senate Judiciary Committee hearing Tuesday investigating ethics on the nation’s highest court, but received pushback from Republican committee members, who said the probe is politically motivated.

This hearing comes after two media reports detailing improper gifts and land deals involving Supreme Court justices.

ProPublica recently published an article revealing that Justice Clarence Thomas had not disclosed two decades’ worth of luxury vacations paid for by Republican mega-donor Harlan Crow, who has also bought real estate from Thomas.

Thomas described Crow as a dear friend, saying he didn’t believe he needed to disclose those vacations.

Then, just last week, Politico released a report that Justice Neil Gorsuch had not disclosed the identity of a person who bought property from him in Colorado.

That person ended up being the head of a law firm with several cases before SCOTUS.

In opening statements Tuesday Durbin pointed out that Congress and the judicial branch created ethics laws and standards for federal judges, and argued an enforceable code of conduct is needed for the Supreme Court as well.

“We are here today because the Supreme Court of the United States of America does not consider itself bound by these rules,” Durbin said.

Referencing the recent reports about Thomas and Gorsuch, Durbin said it’s “pretty clear” to most that this is not the ordinary course of business, and said it should not be a standard for those in public service.

“We wouldn’t tolerate this from a city council member or alderman,” Durbin said. “The highest court in the land should not have the lowest ethical standards.”

But Republicans accused Democrats of wanting to destroy the court’s legitimacy and targeting conservative justices because they’re not getting the Supreme Court decisions they want.

While he, too, says he wants the Supreme Court to be more transparent and have rules the public can relate to, Sen. Lindsey Graham (R-South Carolina) at the same time added that he’s never wanted Congress to take over the court’s ability to regulate itself.

“This assault on Justice Thomas is well beyond ethics,” Graham said. “It is about trying to delegitimize a conservative court that was appointed through the traditional process.”

One of those who testified was Jeremy Fogel, a former federal judge for the United States District Court for the Northern District of California, who pointed out that trust in the courts has eroded for a number of reasons, including political partisanship, controversial decisions, and social media mis- and disinformation.

“In this fraught environment, I believe that the absence of a formal structure for defining and validating the ethical rules governing the Supreme Court justices is untenable,” Fogel said. “Too many Americans already think that the justices decide cases based on their political preferences and alliances instead of the law. Lack of clarity about the justices’ ethical obligations only feeds that perception.”

Michael Mukasey, a former United States Attorney General and former U.S. District Judge for the Southern District of New York, agreed with other witnesses and senators that a conflict of interest can undermine confidence in the Supreme Court. 

However, he added it needs to be said exactly what that conflict is. 

“People often say the appearance of conflict and feel this is a nice vague term they can use to cover a concern about something else,” Mukasey said. “I think if you allege in as to a particular Supreme Court justice that there is an appearance of a conflict or appearance of impropriety, you have some obligation to articulate what it is that appears.”

Chief Justice John Roberts, Fogel said, has previously explained that the Supreme Court differs from lower courts, and as such, it would be inappropriate for it to adopt an identical code of conduct as one for federal judges.

Although Fogel concurred with Roberts on that point, the former judge said that doesn’t mean the Supreme Court should have no formal code at all.

Instead, Fogel said, it could adopt a “modified code that accounts for these differences.”

As part of this hearing, members invited Roberts to testify, but he declined to do so.

“Testimony before the Senate Judiciary Committee by the chief justice of the United States is exceedingly rare, as one might expect in light of the separation of powers concerns and the importance of preserving judicial independence,” Roberts said in a statement.

Durbin criticized the chief justice’s refusal to speak at the hearing, as well as his reasoning for doing so, on Tuesday.

“Answering legitimate questions from the people’s elected representatives is one of the checks and balances that helps preserve the separation of powers,” he said.

Graham pointed out, though, that Roberts’ ethics statement declining to testify at the hearing was not only signed by himself, but all nine judges.

Addressing senators’ concerns about political attacks on justices, Amanda Frost, a research professor at the University of Virginia, said there would be less with better legislation. 

“If ethics laws were strengthened or passed by this congress they would apply to all the justices,” Frost said. “If there was more transparency in the court and its process for dealing with ethical problems, then we wouldn’t have certain reports publicizing certain justice’s problems. We’d have transparency about each and every justice, whether they were abiding by the rules and what should happen next.”

Two prominent constitutional experts, according to the Washington Post, said to the committee in prepared testimony that while Congress can impose a code of conduct for justices, it cannot order the Supreme Court to come up with rules on its own. 

Better, enforceable ethics structures at the Supreme Court could be created immediately, Kedric Payne, vice president, general counsel, and senior director of ethics at the Campaign Legal Center in Washington, D.C., said.

“All they need is to establish an office within the Supreme Court that has ethics experts or professionals who could provide advice on the existing rules and can handle any new rules that are enacted,” Payne said. 

NewsNation digital producer Devan Markham contributed to this article.