Evangelicals are feeling the first rumblings of a schism with the Republican Party. Their 40-year-old alliance, one of the most durable in modern politics, could fracture — and Donald Trump's cruel, racist immigration policies would largely be to blame.

The evangelical vote has long been divided on immigration. Many evangelicals supported Congressional efforts to pass a comprehensive immigration reform package. But in contrast to issues like LGBT rights and abortion, these evangelicals lacked the clout to press the party on immigration, in part because evangelicals were not as united as they are with culture war issues, and in part because anti-immigrant backlash is so intense.

But while the evangelical divide on immigration is nothing new, Trump's candidacy is making it deeper and wider than ever before. This is not just because of his harsh rhetoric against Mexican immigrants, most of whom are Christian, or his calls to deport millions of immigrants, breaking up families if need be. It's also because he is seen as irreligious, misogynistic, and untrustworthy on social issues, giving evangelicals who also support immigrants and refugees additional reason to part ways with the GOP.

Their ranks are larger than you might think. According to recent polling from the Public Religion Research Institute, a slim majority (53 percent) of white evangelicals believes that immigrants "threaten traditional American customs." But that view is far from monolithic; white evangelical opinion on immigration is marked by significant generational and educational divides. A majority of younger white evangelicals — 55 percent — say "newcomers from other countries strengthen American society," and 33 percent say newcomers "present a threat to American culture." Those views are reversed among older evangelicals, with 57 percent saying newcomers present a threat. Similarly, white evangelicals without a degree past high school hold more anti-immigrant views than their college-educated peers.

This divide is explosive not just in the context of the presidential campaign but, possibly more crucially, within the party at the state level.

Take South Carolina. Evangelical advocates for refugees, including humanitarian organizations that contract with the federal government to resettle them in the United States, are up in arms over a troubling bill that passed the Palmetto State's Senate just before Easter. If the bill becomes law, it would require faith-based sponsors of refugees to enter information about individual refugees into a state database, and could hold the sponsors strictly liable in civil suits if a refugee they resettled commits a terrorist or criminal act.

Evangelical opponents of the bill are worried not just because of the impact it could have on refugees and their efforts to assimilate them in their new home. They charge that it is also an infringement of the religious freedom of evangelicals who serve the refugees, claiming the bill aims to thwart them from carrying out a biblical command to serve the vulnerable. And they worry the bill will keep out Christian refugees fleeing the Islamic State. One of the leading evangelical humanitarian organizations partnering with churches to serve refugees, World Relief, is a target of the bill. Although the group has resettled a small number of Muslim refugees in South Carolina, the majority are Christian, some of whom are escaping religious persecution.

But while these charges undercut two major talking points the GOP often tells evangelicals, they've largely been ignored. Claims that the bill is an infringement of religious freedom have been met with crickets. And one South Carolina congressman even accused World Relief, a non-profit, of having a “profit motive related to settling these refugees.”

Yet while his words likely offended a major portion of South Carolina's evangelicals, it probably struck a chord with another. South Carolina is a microcosm of the evangelical divide on immigration. While many evangelicals in the state have expressed full-throated opposition to the bill, others, including church leaders, can be more muted, reflecting the split they know exists within their congregations.

Now, the GOP certainly could have been in the same place at the national level had Trump not been the frontrunner at this point in the presidential campaign. Another 2016 hopeful could have have stoked a similar anti-refugee and anti-immigrant backlash after Paris, San Bernardino, and Brussels (and indeed Trump's current chief rival, Ted Cruz, falls in that camp). But because of Trump's other, clear shortcomings as a candidate appealing to the GOP's evangelical base, his nomination could lay the groundwork for a rupture that might have not happened without him.