The Roberts court has redefined the separation of church and state. This term may show how far it will go. Women pray outside the Surpeme Court last year. (Jabin Botsford/The Washington Post) Religion is on a winning streak at the Supreme Court — and faith-based advocates are pushing to extend it in coming months, hoping to cement a shift in American life that could be one of the current court’s biggest legacies.

The justices are poised to decide in their new term whether a Catholic school that does not accept the children of gay parents can participate in a Colorado prekindergarten program. It is likely to hear arguments on whether the Ten Commandments can be posted in public schools. And it may take a case from Amish parents seeking an exemption from New York’s vaccine mandate for their school-age children.

Over the past five years, the Supreme Court has ruled in favor of expanding the rights of religious groups in nearly every case that has come before it, according to a data analysis conducted for The Washington Post. Since the 2020 term, the court has sided with those groups in seven of those eight cases.

This term’s cases may test how far the court is willing to go in remaking the wall between church and state in America. Recent victories for religious-rights organizations, along with a slew of earlier decisions by the court led by John G. Roberts Jr., already have greatly expanded the presence of religion in public life.

The decisions have granted religious organizations exemptions from antidiscrimination and health care mandates. They have allowed public benefits to flow to religious schools. They have given parents the right to take their children out of school lessons that include books with LGBTQ+ themes.

People demonstate at the Supreme Court in 2025 in support of being able to opt children out of classes involving LGBTQ-related content.

The Supreme Court’s 6-3 conservative majority could continue down that path this term, having already accepted three cases involving religious plaintiffs, with more expected.

One potential blockbuster involves a Catholic preschool in Colorado that has sued to join the state’s universal prekindergarten program. Colorado requires participating schools to sign an agreement not to discriminate on the basis of sexual orientation, among other factors.

The school, run by St. Mary Catholic Parish , says accepting the children of gay and transgender parents would interfere with its teaching that true marriage exists only between a man and a woman. The state argues that excluding these children is openly discriminatory. Arguments in the case are scheduled for November.

“What’s happened in the last 20 years is the court has treated the government’s arguments for restricting religion very skeptically ,” said Thomas C. Berg, a law professor at the University of St. Thomas who supervises the school’s religious-liberty appellate clinic.

Berg, whose clinic typically files friend-of-the-court briefs in support of religious organizations, added that “it’s very easy to see St. Mary’s as the next case in this progression of protecting religious exercise.”

The court’s shift on religion reflects profoundly different views of what the Constitution means when it says the government cannot prohibit the “free exercise” of religion.

The Supreme Court has long been skeptical of letting religious groups benefit from taxpayer-funded programs, for example, but the current justices are more likely to see excluding those groups as discriminatory. Although earlier courts worried that public displays of Christian faith by official figures could cow minority groups, the Roberts court has been loath to curtail them.

This term’s cases may test whether the justices have reached their limit in welcoming religion into the public sphere.

The case involving the Ten Commandments, which the justices are widely expected to take up, confronts a 46-year-old Supreme Court precedent saying that posting the Ten Commandments in public-school classrooms violates the Constitution’s promise of the separation of church and state. The high court in 2022 abandoned another five-decade-old precedent when it ruled in favor of a high school football coach who prayed after each game on the 50-yard line.

Former high school football coach Joe Kennedy kneels in front of the court after his case was argued in 2022.

The court may also take up a case involving an Amish community that is seeking an exemption from New York’s vaccine mandate for schoolchildren. During the height of the coronavirus pandemic, the justices ruled overwhelmingly for religious plaintiffs seeking carve-outs from health policies, though it has stopped short of exempting them from general vaccine mandates.

The Amish case could give the justices an opportunity to change that. Regardless, it is increasingly clear that expanding religious free-exercise rights has become one of the defining themes of the Roberts court.

In the five decades before Roberts became chief justice in 2005, the Supreme Court voted in favor of expanding religious rights about half the time, according to a data analysis conducted by Washington University in St. Louis political science professor Lee Epstein and Andrew D. Martin and Michael J. Nelson of Penn State.

Those rulings usually were in support of religious minorities, not mainstream Christian groups, according to Epstein’s research.

By contrast, in the two decades of the Roberts court, decisions favoring the expansion of religious rights jumped to 86 percent.

During Roberts’s first 15 years leading the court — when conservatives held a 5-4 majority — the court issued a “pro-religion” decision in 80 percent of the 15 cases it decided, the research shows. The proportion has only grown since 2020, when Justice Amy Coney Barrett, a religious conservative, replaced Justice Ruth Bader Ginsburg, cementing a 6-3 conservative majority.

In one case, the court overturned a Maine law that barred religious schools from participating in a tuition assistance program. In another decision, this one unanimous, the court found that the city of Philadelphia could not refuse to contract with a Catholic foster care organization that declined to place children with same-sex couples.

The only recent case where the court did not rule in favor of expanding religious rights came in 2025 — and it could have gone the other way, had all the justices participated. The court deadlocked 4-4 on whether Oklahoma could establish a religious charter school, after Barrett recused herself due to her close friendship with a professor who had advocated for the creation of the school.

The pro-religion bent of the Roberts court is largely driven by the court’s conservative members, according to Epstein’s research. From 2005 to 2019, the court’s Republican appointees voted in favor of expanding religious rights 83 percent of the time, compared with Democratic appointees who cast such votes only 47 percent of the time.

In contrast to past courts, many of the favorable rulings by the Roberts court have come in support of mainstream Christian groups and plaintiffs, Epstein and Eric A. Posner, a University of Chicago Law School professor, wrote in a 2022 paper .

Epstein and other scholars have found that the Catholic justices are significantly more likely to vote in favor of religious groups than non-Catholic justices. Six of the nine justices are Catholic: Roberts, as well as Justices Clarence Thomas, Samuel A. Alito Jr., Sonia Sotomayor, Brett M. Kavanaugh and Barrett. Justice Neil M. Gorsuch grew up Catholic and later became Episcopalian.

Chief Justice John G. Roberts Jr., center, stands with Justices Elena Kagan, Neil M. Gorsuch and Amy Coney Barrett in February. (Kenny Holston/Pool/New York Times) Only one of the justices belongs to a non-Christian minority. Justice Elena Kagan, who is Jewish, regularly dissents from the majority’s opinions expanding the role of mainstream religion in public life. Sotomayor, a liberal justice whom Epstein’s research found is less “devout” than other Catholics on the court, also regularly dissents from such decisions.

The court’s rulings are “driven by this general desire to return free exercise to its glory of a general right to religious freedom,” said Zalman Rothschild, an assistant professor at the Cardozo School of Law in New York who has written extensively about religion and the law.

That means “that any time a law interferes with your religious beliefs, you presumptively have a free-exercise right against the government — and the government now has to show why it can’t cater to your religious convictions and practices,” Rothschild added. “If that’s the motive, then it’s not surprising that [the Supreme Court] is constantly siding with religion.”

Rachel Laser, president and CEO of Americans United for Separation of Church and State, put it more bluntly.

“The biggest concern is the way the court has turned religious freedom on its head,” said Laser, whose organization is participating in the case challenging Texas’s Ten Commandments law. It has “misused religious freedom as a way to allow people to impose their religion on others and undermine church-state separation, which is the true guard for religious freedom .”

The court occasionally has ruled against religious plaintiffs in recent cases, but those did not squarely concern the free exercise of religion.

In June, for example, the high court ruled in an ideologically split decision that a Rastafarian man could not sue prison officials who forcibly shaved off his dreadlocks. But the decision focused on the technicality of whether an inmate could sue individual prison officials, as opposed to the prison itself.

Rick Garnett, a professor at Notre Dame law school, cautioned that not all the court’s decisions in favor of religious groups have been strictly divided along ideological lines. Among the cases he cited was a unanimous decision in 2012 exempting a religious school from an employment discrimination lawsuit.

He also disputed the notion that the Roberts court has distorted the promise of religious freedom. Instead, it has undertaken “doctrinal repair” of cases that disfavored religious exercise, he said.

Citing the Ten Commandments case, he added, “It remains to be seen whether this doctrinal repair that I’m talking about is going to be extended into this realm of what’s happening in the public school classroom. ”