Questions from three U.S. senators to a nominee to a federal appeals court are raising the eyebrows of some Catholics who see in them a lingering bias against Catholics serving in public life.

During a confirmation hearing on Wednesday for Amy Coney Barrett, a law professor at the University of Notre Dame who has been nominated to serve on the 7th Circuit Court of Appeals, Senator Dianne Feinstein, a Democrat from California, grilled the nominee about her views on Roe v. Wade and whether her religious views would hurt her ability to be impartial on the bench. The senator referenced speeches given by Ms. Barrett, who is Catholic, to conservative legal groups and a 1998 article she co-authored about the obligations of Catholic judges in cases involving the death penalty.

“When you read your speeches, the conclusion one draws is that the dogma lives loudly within you,” Ms. Feinstein said. “And that’s of concern when you come to big issues that large numbers of people have fought for for years in this country.”

Ms. Barrett had addressed the concern about personal viewpoints affecting rulings at the start of the hearing. In response to a question about the article from the committee chairman, Senator Chuck Grassley, a Republican from Iowa, she said, “It is never appropriate for a judge to apply their personal convictions, whether it derives from faith or personal conviction.”

Ms. Barrett and John Garvey, her law professor at the time and now the president of the Catholic University of America, argued in the 1998 article that Catholic judges who share the church’s view on the death penalty should consider recusing themselves from cases in which they feel they cannot rule impartially because of their faith.

Leading up to Wednesday’s hearing, the left-leaning Alliance for Justice had published an article saying Ms. Barrett “has asserted that judges should not follow the law or the Constitution when it conflicts with their personal religious beliefs. In fact, Barrett has said that judges should be free to put their personal views ahead of their judicial oath to faithfully follow the law.”

“I suspect what really troubled them was that, as a Catholic, her pro-life views might extend beyond criminal defendants to the unborn.”

Mr. Garvey rejected that interpretation. “Barrett [and I] said no such thing. We said precisely the opposite,” he wrote in an op-ed published Thursday in the Washington Examiner. He went on to write that he sees anti-Catholicism lurking behind the questions from Senator Feinstein as well as from Senators Richard Durbin, a Democrat from Illinois, and Mazie Hirono, a Democrat from Hawaii.

“Senators Durbin, Hirono, and Feinstein seemed particularly troubled by Barrett’s Catholicism. I don’t think they objected to her membership in the Church plain and simple. That would violate the Religious Test clause of the Constitution,” he continued. “I suspect what really troubled them was that, as a Catholic, her pro-life views might extend beyond criminal defendants to the unborn. If true, the focus on our law review article is all the more puzzling. After all, our point was that judges should respect the law, even laws they disagree with. And if they can’t enforce them, they should recuse themselves.”

Though the article in question addressed the death penalty, Ms. Feinstein pressed Ms. Barrett on abortion, asking whether she believed Roe v. Wade was correctly decided and if it was now precedent. Ms. Barrett said should she be confirmed as an appeals court judge, she would “absolutely follow” Supreme Court precedent on abortion.

Senators Durbin and Hirono also asked Ms. Barrett about her Catholic faith during the hearing. Mr. Durbin, who noted during his questioning that he is also Catholic, took issue with Ms. Barrett’s use of the phrase “orthodox Catholic” in the 1998 journal article. He said some Catholics use that phrase to cast aspersions on fellow believers, including those who hold what are considered liberal positions on social issues.

“There are many people who might characterize themselves orthodox Catholics who would now question whether Pope Francis is an orthodox Catholic. I happen to think he’s a pretty good Catholic,” Mr. Durbin said.

“I agree with you,” Ms. Barrett responded.

“Do you consider yourself an orthodox Catholic?” the senator asked.

“If you’re asking whether I’m a faithful Catholic, I am, although I would stress that my own personal church affiliation or my religious belief would not bear on the discharge of my duties as a judge,” Ms. Barrett replied.

“Do you consider yourself an orthodox Catholic?” asked Senator Richard Durbin.

Senator Ben Sasse, a Republican from Nebraska, suggested that the questions asked about Ms. Barrett’s faith seemed to violate the constitutional prohibition against a religious test for public office. “Some of the questioning that you’ve been subjected to today seems to miss some of these fundamental constitutional protections that we all have,” he said.

But Mr. Durbin and Ms. Feinstein both stood by their questions, telling the National Review that Ms. Barrett’s public speeches and writings about the intersection of law and faith invited such inquiries.

Ms. Feinstein’s office pointed to a 2006 speech Ms. Barrett gave to graduates of Notre Dame’s law school, in which she said their legal career was a “means to an end,” which she said was “building the kingdom of God.”

“Professor Barrett has argued that a judge’s faith should affect how they approach certain cases,” Ms. Feinstein’s press secretary told the National Review. “Based on this, Senator Feinstein questioned her about whether she could separate her personal views from the law, particularly regarding women’s reproductive rights.”

Richard Garnett, one of Ms. Barrett’s colleagues at Notre Dame, told America that he thinks the senators who took issue with the nominee’s writing “misunderstood and mischaracterized her academic work.” He said the questions about her faith appeared to harken back to a time when Catholics were seen as unable to carry out public office because of their religion.

“I don’t like to speculate about motivations, but it seems clear to me that the remarks from both of those senators reflected the view that a Catholic nominee for the federal bench is of special concern because the senators are bringing certain presumptions that a Catholic jurist won’t follow the law,” he said. “That assumption is unfortunate and reflects some sort of prejudice.”

“You can’t say that our faith on the one hand has ramifications for politics, law and the common good and on the other hand expect not to answer questions about it.”

He said that Ms. Barrett took the same tack as previous nominees for federal judgeships in declining to answer questions about specific cases, saying that such answers “would create bad impressions for litigants” in future cases.

But Cathleen Kaveny, the Libby Professor of Law and Theology at Boston College, said that individuals must “be careful about accusations of anti-Catholicism,” noting that the faith has public elements embedded within it that are fair game for questions. “You can’t say that our faith on the one hand has ramifications for politics, law and the common good and on the other hand expect not to answer questions about it and claim that faith is purely private,” she told America.

Ms, Kaveny said that when an individual publicly identifies with a certain faith, it is appropriateappropriate for lawmakers to question how the tenets of that faith might influence how they would rule on the bench. “Whether a candidate for the judiciary thinks it’s prudent to answer those questions is another question,” she said.

Social media lit up with reaction to Ms. Feinstein’s questioning, with the hashtag #DogmaLivesLoudly used by a number of people to express their views on the hearing. Some public figures also weighed in.

Kirsten Powers, a CNN political commentator and a Catholic, wrote in a tweet that Ms. Feinstein’s questions were “religious bigotry, pure and simple.” U.S. Representative Jim Banks, a Republican from Indiana, tweeted that “Senator Feinstein should apologize for anti-Catholic attack.”

Michael Wear, who worked in the Obama administration as a faith-based adviser, wrote in a tweet of Ms. Feinstein’s remarks, “She basically calls the nominee a Papist. Talk about social views from the 1950s.”

Ms. Barrett’s nomination has received the support of her colleagues at Notre Dame. In an op-ed published in the South Bend Tribune, Jennifer Mason McAward, a self-described “pragmatic moderate,” noted that the entire full-time law faculty at the university signed a letter supporting Ms. Barrett’s nomination.

Michael J. O’Loughlin is national correspondent at America and author of Hidden Mercy: AIDS, Catholics, and the Untold Stories of Compassion in the Face of Fear.