Leading the crowded GOP field for the White House, real estate mogul and reality television personality Donald Trump will take center stage in Thursday’s Republican primary debate in Cleveland, where he’s expected once again to highlight an issue that has fueled his popularity: opposition to undocumented immigration.

While that stance is nothing new for politicians, sometimes on both sides of the aisle, Trump’s comments are notable for their hostility toward illegal Mexican immigrants specifically. During his campaign launch earlier this summer, Trump suggested that the Mexican government sends “the worst elements” of Mexican society to the United States, in the form of drug dealers, rapists, and other criminals.

While his poll numbers remain strong even in the wake of those comments, some retailers, media outlets, and restaurateurs have severed ties with Trump, and ahead of Thursday’s debate, hosted by Facebook and Fox News, Trump can add one more group of people unhappy with his comments: Roman Catholic bishops.

New York Cardinal Timothy Dolan, who leads an archdiocese with a huge Hispanic population, placed Trump in the dark history of American chauvinism last week, writing in the New York Daily News, “Nativism is alive, well – and apparently popular!”

Nativisim thrived in the mid- to late-1800s, Dolan wrote, an ideology driven by those who “believed the immigrant to be dangerous, and that America was better off without them. All these poor degenerates did, according to the nativists, was to dilute the clean, virtuous, upright citizenry of God-fearing true Americans.”

Americans, Dolan wrote, have two choices when it comes on how it approaches the issue of immigration today. One option is to view immigrants as an “unwashed, ignorant, bothersome brood” of “criminals and misfits who threaten ‘pure America.’”

But the “more enlightened and patriotic view,” he wrote, is to see “the immigrant as a gift to our nation.”

While chiding Trump’s comments, Dolan wrote that he’s “not in the business of telling people what candidates they should support,” but that he nonetheless takes “seriously the Bible’s teaching that we are to welcome the stranger, one of the most frequently mentioned moral imperatives in both the Old and New Testament.”

Dolan’s comments come at a time when Catholic bishops in the United States are pushing lawmakers to pass comprehensive immigration reform, including a pathway to citizenship for the estimated 11 million undocumented immigrants living in the United States. That position is nothing new, however, as Catholic bishops have long championed reform, sometimes putting the Church at odds with both political parties.

Earlier this year, for example, the US Conference of Catholic Bishops released a report highlighting abuses in US immigrant detention centers, calling on the Obama Administration to reform how it processes and charges undocumented immigrants and noting that the number of detained immigrants is at an all-time high.

But with Trump surging in the polls, the rhetoric about immigration has become increasingly hostile, some bishops warn. While Dolan’s column is unique in specifically calling out Trump, other bishops have reminded their flocks where the Church stands on the issue.

Bishop Kevin Farrell of Dallas, for example, condemned what he called the “déjà vu of immigrant bashing” in a blog post last week, reminding American Catholics that they were once subject to the kind of harsh words used by Trump.

“Campaigns to mark Catholics as subversive were waged by the Know Nothings and the Ku Klux Klan, who maintained that Catholicism was antipathetic to American democracy,” he wrote.

“Of course, we are an immigrant nation, and those whose parents and grandparents were reviled by Nativists are now our legislators, judges, scientists, academics … and politicians,” he wrote. “The ghost of Nativism again prowls our land. The vilifiers and the vilified are different, but the script is the same.”

Catholics in Los Angeles participated in a special day of prayer July 18 about immigration, during which Archbishop Jose Gomez called for comprehensive immigration reform.

Gomez, who leads the US bishops’ committee on migration issues, told CNN en Espanol that he’s reluctant to wade into political waters, but nonetheless called Trump’s comments “not right.”

The archbishop, the highest-ranking Hispanic prelate in the United States, reiterated his dismissal of Trump during a press conference later in the month, saying he hadn’t paid attention to the candidate’s comments, but would nonetheless press on with calls for federal action on the issue.

Responding to a reporter’s question about Trump, Gomez laughed and said, “I’m not a politician, I’m a pastor, so I just really haven’t paid too much attention to what he’s said.”

“Every immigrant that comes to this country is a human person and deserves respect, consideration, because they are just people like us, men and women with families with children, children that need their parents,” he continued. “We hope that everybody in this country continues to respect the dignity of the human person.”

And in New Jersey, Bishop Dennis Sullivan of Camden urged Italian-American Catholics to apply their own history as victims of anti-immigration hysteria to the present situation.

Speaking to the Our Lady of Mount Carmel Society, Sullivan said their ancestors “followed traditions they knew from the old country,” and said that “all of us here own an enormous debt to our immigrant ancestors.”

Perhaps unsurprisingly, in an NBC/Wall Street Journal poll released Sunday, 75 percent of Latinos hold an unfavorable view of Trump, although he leads the GOP field with 19 percent of poll respondents choosing Trump.

About 41 percent of the US Catholic Church identifies as Hispanic, up 6 points from 2007, according to the Pew Research Center.