Attorney Theodore Boutrous, of Gibson Dunn, outside the U.S. Supreme Court on the day of arguments in the case challenging California’s Prop 8 legislation. March 26, 2013. Photo by Diego M. Radzinschi/THE NATIONAL LAW JOURNAL.

President Donald Trump’s travel ban is “un-American” and “un-Catholic,” a team of partners at Gibson, Dunn & Crutcher told the U.S. Supreme Court in an amicus brief filed on behalf of a group of bishops Tuesday.

The United States Conference of Catholic Bishops filed its brief with the high court as it considers whether to continue a stay on the Ninth Circuit’s ruling last week that exempted roughly 24,000 refugees from the travel ban executive order. The bishops argued the order’s language shows an animus toward Muslims that’s reminiscent of the long history of discrimination against Catholics in the United States, and violates the core tenets of the Catholic faith.

“Such blatant religious discrimination is repugnant to the Catholic faith, core American values and the United States Constitution,” the brief said.

Representing the bishops pro bono are Gibson partners Ted Boutrous, Joshua Lipshutz and Ethan Dettmer. They are joined by in-house lawyers for the Conference, including Anthony Picarello Jr., Jeffrey Moon and Carlos Miranda.

The Supreme Court temporarily stayed the Ninth Circuit’s decision Monday in response to an emergency request from the U.S. Department of Justice. The court said it will issue another order after it heard from the plaintiff, the state of Hawaii, which filed its response today. The court will also hear oral arguments on the merits of the travel ban case Oct. 10, and amicus briefs have been piling up in the prelude to those arguments.

The brief argued the court should “relegate” the executive order to the “dustbin of history.” It said the bishops are concerned about the “threat it poses to religious liberty in general and Muslims in particular.” It also cites several quotes from Pope Francis: “The yardstick we use for others will be the yardstick which time will use for us,” the Pope told Congress in 2015.

The bishops note that the Catholic Church is committed to helping migrants and refugees around the world, and acts as a resettlement agency for refugees in the United States. Through these efforts, the Conference has witnessed the devastation families face when their loved ones cannot enter the country, according to the brief.

“Such cruel and inhumane treatment, denying refugee children life-saving entry to the United States based on an executive order clearly motivated by anti-religious bias, is both un-Catholic and un-American,” the brief said. “It is incumbent upon this court to say so.”