WILLIAM BRANGHAM: Today's Supreme Court is no stranger to controversy.

Earlier this week reporting by ProPublica revealed that Justice Clarence Thomas took undisclosed lavish trips funded by a Republican megadonor.

This comes as the country waits to see just how the justices will rule in a number of contentious cases dealing with affirmative action, voting rights and LGBTQ rights.

Last week, John Yang sat down with Supreme Court analyst Joan Biskupic to discuss her new book, that details the courts recent conservative shift, and how that could shape the country's future.

JOHN YANG: The most prominent results so far of the Supreme Court's rightward shift may be last year's overturning of Roe vs. Wade racing the nearly half century old right to seek an abortion.

But there are many other consequences whose effects will be felt for generations to come.

It's all detailed in a new book, Nine Black Robes: Inside the Supreme Court's Drive to the Right and Its Historic Consequences.

The author is Joan Biskupic, the Senior Supreme Court Analyst for CNN.

Joan, thanks for joining us.

How crucial were the four years where the Republicans controlled both the White House and the Senate in this shift to the right?

JOAN BISKUPIC, Author, " Nine Black Robes": Completely crucial.

You know, Donald Trump got three appointees and four years.

That's really remarkable.

It's not, you know, a record but it's remarkable for modern history.

And the reason he was able to get those three appointments through so speedily was because he had a Republican Senate and he had a real partner and Senate Majority Leader Mitch McConnell.

JOHN YANG: You write about the whole apparatus that there is to try to get the judiciary to be more conservative Leonard Leo, the Federalist Society.

How Central was Donald Trump to that?

Could this have happened without Donald Trump?

JOAN BISKUPIC: A version of it could have happened without Donald Trump, but it was crucial to have Donald Trump, his White House Counsel, Don McGahn, Senate Majority Leader Mitch McConnell, and Leonard Leo, as you mentioned, all working together to pick people and to speed them through the process.

Let's just use as an example, the third appointee Amy Coney Barrett, Ruth Bader Ginsburg dies on September 18.

She's buried at the very end of the month.

And at the very end of September is when Donald Trump announces the nomination of Amy Coney Barrett.

Her hearings happen almost immediately.

She's confirmed at the end of October, and we're right at the election.

Contrast that to what happened in 2016 when Mitch McConnell said upon Antonin Scalia's death in February of 2016, there is not enough time to have a new Justice confirmed until the November election all those months versus just those few weeks and days, that shows how Donald Trump working with this team made such a difference.

JOHN YANG: You write of Donald Trump that his effect on the justices relationships with each other, was even at times pernicious as he sowed distrust.

JOAN BISKUPIC: I noticed something happening as they were all maneuvering differently inside to sort of counteract his effort to undermine the integrity of the judiciary, you know, think of the disdain that Donald Trump had shown toward the judiciary, even as a candidate, you know, mocking a judge who ruled against him as a Mexican judge.

And then he had that one pretty unprecedented clash with the Chief Justice, when he disparaged a judge who ruled against his administration as just an Obama judge.

And that was when Chief Justice John Roberts said there are no Obama judges, there are no Trump judges, Clinton judges, Bush judges, but that showed how much the chief and some of the other justices were trying to counteract the idea that the justices were not going to be neutral based on their politics.

But the bottom line is that we have a cord that has signaled to the American public, as polls reflect that it is politically energized.

JOHN YANG: You cite the Chief Justice who famously said in his confirmation hearings, that he was going to be an umpire just calling the balls and strikes.

But you also write that the conservatives on this court seem intent on rewriting the law?

JOAN BISKUPIC: A lot of our viewers will remember that the Chief Justice John Roberts broke away from the five conservatives to his right in the Dobbs ruling that reverse Roe v. Wade, he did not want to go so far so fast.

But John Roberts has been with the others on the conservative side to rollback racial remedies, to restrict regulations.

And much of that involves reversing precedent.

You're lowering the wall of separation between church and state, diminishing the ability of the federal government to regulate the environment, public health and safety.

And then also on social policy issues, we have many ongoing clashes between religious interests, and LGBTQ rights.

And those that's another area where I think we're going to increasingly see the core siding with religious interests.

JOHN YANG: Have you seen a change in the three remaining liberal justices and how they respond to this?

JOAN BISKUPIC: Let's just take Justice Elena Kagan, for example, she of the three remaining could more align herself with a center to broker a deal.

So she would often work with Chief Justice John Roberts and Justice Stephen Breyer, who has since retired to try to bring about a compromise.

But she essentially doesn't have a partner in that effort toward five votes anymore.

So I have found that she is a little louder in her dissents, and, you know, moving almost more to the left to complain about the majorities rulings to call attention to things and it makes such a difference to be down just one justice.

It's because there's this cushion now on the right wing, you know, they can lose one and still have a majority.

We will have to see how it all shakes out.

JOHN YANG: You talk about finding compromises on the court, and you expose a lot of it.

You write that justice has declined cases, delayed cases, or made compromises to avoid a 5-4 conservative liberal split.

This is obviously when Ruth Bader Ginsburg was still alive.

Talk about how this deal making and trading goes on?

JOAN BISKUPIC: I'll bring you back to 2020 when the Supreme Court was handling two cases that involve clashes over Trump documents that the Manhattan DA wanted and House committees wanted.

And when the justices first considered these two cases, they were bitterly split along five to four lines, the Chief Justice did not want to produce 5-4 rulings just because of how polarizing Donald Trump had been.

And he worked with other justices he compromised.

And in the end, the chief was able to produce two, seven to two rulings that went against Donald Trump in these cases, but yet, you know, preserved the offices of the presidency and also I think, tried to preserve the stature of the judiciary.

JOHN YANG: In your final chapter, which looks at the Dobbs decision which overturn Roe v. Wade, you're right.

The court had no middle, no center to hold, what's the effect of that?

JOAN BISKUPIC: It's so significant for the nation.

You know, obviously we saw most enrolling back all these decades of reproductive rights and women's privacy.

But you -- there's no incentive for compromise the way there had been when things were more narrowly divided.

The Supreme Court is considering the future of campus affirmative action at Harvard and the University of North Carolina.

Those are cases that you are so unlikely to see a middle ground compromise as we saw back in 2003 when in the University of Michigan cases and way back when to the Bakke case in 1978.

That's the difference, John.

JOHN YANG: The book is, Nine Black Robes.

The author is Joan Biskupic, the Senior Supreme Court Analyst at CNN.

Joan, thanks so much.

JOAN BISKUPIC: Thanks, John.

Appreciate it.