(CNN) There's only ever been one Catholic president and Catholics are a declining portion of the US population, but they're holding a strong majority on the US Supreme Court.

When President Donald Trump nominated Brett Kavanaugh to the Supreme Court Tuesday night, Kavanaugh described his Catholic faith and the importance of the church in his life -- from the high school he attended to the Catholic Youth Organization basketball teams he now coaches.

If confirmed, Kavanaugh will replace Anthony Kennedy, who is Catholic. Trump's other nominee, now-Justice Neil Gorsuch, replaced Catholic Antonin Scalia. Gorsuch attends Episcopal churches now, but was raised Catholic. CNN's Daniel Burke has written that about Gorsuch's faith, which he keeps private, and it is a complicated matter.

Every other Republican-appointed Justice on the court is Catholic. And Democrat-appointed Sonia Sotomayor was raised Catholic and during her nomination was described as a "cultural Catholic."

That means six of the nine Justices, two-thirds, have a Catholic background.

The strength of Catholics on the bench is strong, but the number of Catholics in the US is in decline.

Just under a quarter -- 23.9% -- of the US population was Catholic in 2007 and by 2014 that number had fallen to 20%, according to a large study by Pew. (Notably, just 1.9% of Americans were Jewish in that Pew survey, but there are three Jewish Supreme Court Justices.)

But the Pew study also showed Catholics in America are increasingly not white, largely due to the large number of Catholics who are Hispanic (34% in 2014). The number of nonwhite Catholics has been growing, too. They were 35% nonwhite in 2007 and 41% nonwhite in 2014. On the court, Clarence Thomas and Sotomayor, the only nonwhite justices, are Catholic.

The Catholic community is also made up of more immigrants than other American communities. More than a quarter of US Catholics (27%) were born outside the US, although most Supreme Court justices were born or raised in the Northeast of the United States. Fifty-seven percent of Catholics in the study were born in the US to native-born parents. Far more -- 74% of Americans overall -- were born in the US to native-born parents.

The demographics are interesting, but they don't answer the question of why so many Catholics have made their way to the court and whether faith will affect their decisions.

Judicial nominees these days are loath to answer how they'd vote on cases or how they feel generally about issues, especially abortion, which is growing into a key issue of Kavanaugh's nomination since he'll be replacing Kennedy, who was long viewed as a key swing vote protecting the Roe v. Wade legal precedent.

The public at large (57%) supported legal abortion in a 2017 Pew survey, saying it should be legal in all or most cases. Catholics were less supportive, but still a majority (53%) said at the time it should be legal.

But there is a perception that male Catholics on the court are more likely to vote against abortion and perhaps that plays a role among conservatives looking to chip away at Roe.

Given that nominees are likely to stay mum, senators who must vote to confirm them and also want to protect priorities like abortion rights will have to infer.

California Democratic Sen. Dianne Feinstein confronted Amy Coney Barrett, who was on Trump's Supreme Court short list, about her faith during a 2017 confirmation hearing.

"Why is it that so many of us on this side have this very uncomfortable feeling that -- you know, dogma and law are two different things," Feinstein said to Barrett. "And I think whatever a religion is, it has its own dogma. The law is totally different. And I think in your case, professor, when you read your speeches, the conclusion one draws is that the dogma lives loudly within you, and that's of concern when you come to big issues that large numbers of people have fought for years in this country."

That full exchange is well worth watching.

A similar tea leaf reading about Kavanaugh and his thoughts on abortion is already underway, particularly his dissent with a ruling that allowed an undocumented teenager detained at the border to obtain an abortion.

"The majority apparently thinks that the Government must allow unlawful immigrant minors to have an immediate abortion on demand," Kavanaugh wrote.

He wrote in the same dissent that all the judges recognized Roe and the precedents that must be followed. As a Supreme Court justice he could be in a position to change such precedents.

A justice's religion does not, nor should it, matter. But it is certainly a curiosity of modern politics that Catholic and Jewish justices have found such success. It is hard to find demographic information on the federal judiciary at large to see if Catholics justices play an outsize role at the lower levels. A Congressional Research Service report providing a demographic snapshot of the courts did not include religion.

In that Pew survey from 2014, the fastest growing religious group was "unaffiliated," which grew from 16.1% in 2007 to 22.8%, eclipsing Catholicism in the US in the process.

Correction: The percentage of the US population that is Jewish has been updated and corrected in this story. It was 1.9% in 2015, according to Pew.