AMNA NAWAZ: Lawmakers on Capitol Hill are spotlighting recent ethics concerns surrounding the highest court in the land.

In a Judiciary Committee hearing today, senators debated how to address concerns involving Supreme Court justices, including whether they should apply ethical guidelines to the justices themselves.

SEN. RICHARD DURBIN (D-IL): The committee will come to order.

AMNA NAWAZ: Today's hearing focused on the Supreme Court and ethics, unfolding largely along partisan lines, with Democrats arguing the court has failed to uphold its own code of conduct.

SEN. SHELDON WHITEHOUSE (D-RI): Until there is an honest ethics process at the Supreme Court, these messes will continue.

The court has conclusively proven that it cannot police itself.

AMNA NAWAZ: And Republicans accusing Democrats of attacking the court.

SEN. LINDSEY GRAHAM (R-SC): If you want to talk about making the court a better institution, I will be glad to work with you in that regard.

If you want to talk about destroying the court, count me out.

AMNA NAWAZ: Unlike the guidelines federal judges must adhere to, the Supreme Court has no formal ethics code.

Justices are meant to police themselves.

But a series of recent reports documenting justices' failures to disclose gifts and real estate deals has sparked questions about possible reforms.

ProPublica reported in April that Justice Clarence Thomas failed to disclose hundreds of thousands of dollars' worth of gifts, including luxury trips from a billionaire donor.

They later reported the same donor purchased properties from Thomas including Thomas' mother's home, which he still lives in today.

Politico later reported Justice Neil Gorsuch sold a Colorado property to the CEO of a law firm with regular business before the court and didn't disclose that the CEO was a buyer.

SEN. RICHARD DURBIN: Congress not only has the authority to legislate in this area, but the responsibility.

AMNA NAWAZ: In today's hearing, Democrats argued, lawmakers must now act.

SEN. RICHARD DURBIN: The Supreme Court should step up and fix this themselves.

For years, they have refused.

And because the court will not act, Congress must not.

AMNA NAWAZ: But Republicans dismissed the hearing as a liberal effort to undermine the conservative-leaning court.

SEN. JOHN KENNEDY (R-LA): The danger isn't that rogue justices are operating without ethics.

It's that Democrats aren't winning every fight, and they find that reality intolerable.

AMNA NAWAZ: Not in the hearing room, Chief Justice John Roberts, who was invited by Judiciary Chair Dick Durbin to testify.

Roberts declined, calling congressional testimony -- quote -- "exceedingly rare" and cited -- quote -- "the importance of preserving judicial independence."

His letter included a statement on the court's ethics signed by all of the justices, all this as trust in the court is at record lows.

In a recent "PBS NewsHour"/NPR/Marist poll, more than six in 10 Americans said they have little to no confidence in the court.

To help us explore these issues of accountability and confidence in the court.

I'm joined by University of Virginia Law Professor Amanda Frost.

She testified at the hearing before Congress today.

Professor Frost, thanks for being here.

AMANDA FROST, University of Virginia School of Law: Thanks for having me.

AMNA NAWAZ: So, it's worth noting we learned about the gifts to Justice Thomas, Justice Gorsuch's property sales through journalists uncovering the information and then reporting it.

From what you have seen, should that have been information that they disclosed?

AMANDA FROST: Yes, there were clearly failures to follow the ethics laws in those cases.

AMNA NAWAZ: And so what did you make of how the hearing unfolded on those issues today?

AMANDA FROST: Yes.

Well, some of that -- the conversation was productive.

I think there was a general recognition that one of the problems is lack of transparency and that the court is not taking its ethics obligations seriously enough.

So whether Congress takes action through legislation isn't clear, but at least they're shining a light on the issue.

AMNA NAWAZ: Is there context for this conduct?

When you look back in history, are there previous examples of ethical concerns on the court we can compare this moment to?

AMANDA FROST: Yes, there are a few.

I mean, most notably, Justice Abe Fortas way back in the 1960s took a $20,000 payment from a former client.

And that ended -- leading to his resignation, actually.

The public pressure led to that.

And he returned the money, even, but I think he realized that he couldn't withstand that kind of scrutiny because he had been paid while being a justice.

And that was a problem under the ethics laws.

AMNA NAWAZ: What about back in 2016?

I recall when Justice Ruth Bader Ginsburg had made some comments criticizing then nominee Donald Trump and, under public pressure, had to come out and apologize.

Does that all live in the same universe here?

AMANDA FROST: Yes, I think it does.

And I think she violated ethics laws by making those statements, or at least the code of conduct that justices say that they follow.

And she apologized and retracted those statements, as she should have.

Justice Thomas is not alone.

And that's the problem.

We need the court to be more accountable and all of the justices to be following these ethics laws.

AMNA NAWAZ: What about Justice Roberts not appearing today?

Do you think he should have?

And were there questions you would have liked to see him answer about this?

AMANDA FROST: Absolutely.

I was really disappointed that he didn't take the opportunity to have an interbranch dialogue on this question.

And justices testify.

This is not unusual.

And they testify about matters affecting the judiciary.

So I think it would have been helpful if he'd shown up and given the court's perspective.

AMNA NAWAZ: We have noted to, look, both Justice Thomas and Gorsuch are conservative justices.

The calls for accountability right now are largely coming for Democrats.

So this entire conversation seems to be unfolding in a very partisan arena.

How do you look at that?

AMANDA FROST: Yes, unfortunately, it does feel partisan, which is too bad.

I have been talking about this for decades.

And it really shouldn't be viewed as partisan.

I think part of the problem is, because the court is so lacking in transparency, and because it's not making clear what it does to follow ethics laws, the only way we hear about these stories is through occasional investigative reporting.

If the court itself was more transparent, I think it prevents some of these partisan issues from arising in this Democrat-and-Republican-type split.

AMNA NAWAZ: So what does that transparency look like?

What is the remedy here, specific to these examples too, with Justice Gorsuch and Thomas?

What do you believe should happen?

AMANDA FROST: Well, I wish the court on its own would adopt a code of conduct.

Right now,it's the only court at the federal judiciary that does not follow a code of conduct or have one that's binding on it.

And so I wish the court would on its own do that.

If not, Congress could compel them to do so through legislation.

And, hopefully, they would then quickly respond.

And so I'm hopeful that might be what happens in the near future.

AMNA NAWAZ: Do you see that happening in this congressional body?

AMANDA FROST: Right now, unlikely, but the conversation is progressing.

And I think the recent revelations of unethical conduct by a variety of justices have led more people to think reform is needed.

AMNA NAWAZ: Help us understand a little bit more specifically what that code of conduct would call for.

You mentioned, of course, federal judges have to abide by that kind of -- those ethical guidelines.

What specifically do you want to see when it comes to Supreme Court justices?

AMANDA FROST: Yes, so the code of conduct that currently binds the lower court judges, but not the Supreme Court, that would be a great model for the Supreme Court, and they could tweak it as needed for the special situation of being a Supreme Court justice.

It requires things like the courts must make sure never to do something that appears improper, the appearance of impropriety, as well as actual impropriety.

They need to be careful about who they go and speak in front of, who they accept gifts from.

They just have to be more conscious of the fact that they are public figures, and they are deciding cases, and legitimacy of the court is very important to the American people, if they want to trust the outcomes from that court.

AMNA NAWAZ: So, when it comes to the American public and their trust in the Supreme Court, we know that trust, like many major institutions, has been on the decline.

There's a recent "PBS NewsHour"/NPR/Marist poll that asked people how they feel about the court, their confidence in the Supreme Court; 53 percent of Republicans said they feel mostly confident, just 24 percent of Democrats, 39 percent of independents.

And when Justice Alito was asked about that, he answered -- quote -- "Well, yeah, what do you expect when you're day in and day out they're illegitimate, they're engaging in all sorts of unethical conduct, they're doing this, they're doing that?"

Professor Frost, is criticism of the court contributing to their credibility problem?

AMANDA FROST: So, I think there's many reasons why the court is losing some of the public support and trust that it's had in the past, not just these ethical problems.

But I feel like these ethical problems are a self-inflicted wound, because the court, if it was more transparent, if it had an employee responsible for advising them on ethics, so that they weren't making mistakes and constantly failing to follow the law, then these stories would go away, or at least they would be diminished.

And so I feel like the court has injured its own reputation by not taking action.

AMNA NAWAZ: That's University of Virginia Law Professor Amanda Frost joining us today.

Professor Frost, thanks for being here.

AMANDA FROST: Thank you for having me.