On the face of it, Donald Trump is not exactly the sort of leader you would expect Christian conservatives to rally around. He often talks about women, including his three wives, in demeaning and lecherous language; for instance, he characterized his second wife, Marla Maples, as having “nice tits, no brains.” While he was still married to his first wife, Trump and Maples would rendezvous at Manhattan’s Marble Collegiate Church, perhaps not the most pious use of a house of worship. Trump has owned casinos, places regarded by many Christians as dens of iniquity. The billionaire is also boastful, profane, belligerent, insulting, and greedy. He’s said about ISIS, “I would bomb the shit out of them” and take their oil. “I’ve always been greedy,” he has also said, “I love money, right?” That honest self-appraisal might give pause to any Bible reader who remembers St. Paul’s argument that “the love of money is the root of all evil” (1 Timothy 6:10). And although he cites the Bible as his favorite book (better even, he often says in his version of humility, than his own Art of the Deal), Trump shows no signs of familiarity with its contents. 

Yet despite constantly behaving in a manner that calls to mind a decadent Roman Emperor who enjoys feeding Christians to the lions, Trump is doing very well with religious right voters. In Iowa, where evangelical Christians have a stranglehold on the Republican Party, Trump is polling neck-and-neck with Senator Ted Cruz, who has hinged his campaign in no small part on winning conservative Christian votes. But some evangelical voters who should be in Cruz’s camp seem to prefer Trump. Cruz’s recent attempts to smear Trump as an avatar of “New York values” was no doubt aimed at those folks—Godly voters in Iowa and South Carolina who regard the Big Apple as Sodom on the Hudson, but have been leaning toward Trump anyway. 

Trump’s triumphant appearance on Monday at Liberty University, a hotbed of the religious right founded by the late Reverend Jerry Falwell Sr. (and the place where Cruz launched his presidential bid last March)helped to explain the real-estate mogul’s popularity with many religious conservatives. It also betrayed the limits of his appeal. 

Trump received an effusive welcome from the president of the university, Jerry Falwell Jr., who described the candidate as a “visionary” who “lives a life of loving and helping others as Jesus taught in the great commandment.” Falwell also compared Trump to his late father, saying both men stood up to political correctness. This comparison between Falwell and Trump offers some clues as to Trump’s unlikely appeal to the religious right. The elder Falwell fused evangelical Christianity with white identity politics, finding Biblical cause to oppose civil rights in the 1960s and support South African apartheid in the 1980s. 

Like Falwell, Trump has an essentially tribalist (as opposed to theological) view of Christianity. For Trump, Christianity is a marker of identity, one of the dividing lines that separates us from them. That’s why the same paranoid, xenophobic zeal that Trump wants to harness to protect America from undocumented Mexican immigrants and Chinese trade competition is also deployed against Muslims and other non-Christian religions. 

“We’re going to protect Christianity,” Trump said at Liberty. “You look at the different places and Christianity, it’s under siege. I’m a Protestant, I’m very proud of it, Presbyterian to be exact, and proud of it, very, very proud of it, and we’ve got to protect because bad things are happening, very bad things are happening. ... We don’t band together ... other religions, frankly, they are banding together.”

The ominous threat of “other religions” banding together was of a piece with all the shadowy foes of white America Trump likes to evoke, a list that includes Black Lives Matter protestors as well as ISIS, Mexicans immigrants, and foreign trade. Some of the students at Liberty booed Trump’s speech from time to time, and there was tittering when he referred to 2 Corinthians as “Two Corinthians” (which is acceptable usage in England) rather than the more commonly used North American pronunciation “Second Corinthians.” Still, many other students cheered Trump, appearing to share his view of Christianity as a form of white identity politics rather than a universal message. The clapping was especially loud when Trump said he would defend Christianity, and when he took potshots against President Obama and Hillary Clinton.

Writing in the New York Times, BuzzFeed reporter McKay Coppins argues that Trump’s tribalist view of Christianity is of a piece with his nostalgic evocations of a white-dominated America, where both religious and ethnic minorities know their place:

In the Gospel According to Trump, there is only one blessedly normal, all-American faith: mainline Protestant Christianity. The Presbyterians, the Methodists, the Baptists — those believers who once made up this country’s midcentury religious mainstream — are Mr. Trump’s “chosen ones.” He regards their customs and values as essentially as American as apple pie, while all other faith communities, even other forms of Christianity, seem to rest somewhere on a spectrum from exotic to sinister. 

Coppins goes on to cite comments Trump has made that seem to cast a whole variety of faith communities—including Judaism, Seventh Day Adventism, and Mormonism—as exotic. 

But not all conservative Christians are willing to accept Trump as their champion— as the David who will protect them from Goliath and the Philistines. In response to Trump’s appearance at Liberty, the prominent evangelical thinker Russell Moore launched a blistering series of tweets:

As the disparate reactions of Jerry Falwell Jr. and Russell Moore indicate, Trump is polarizing Christians as much as he is dividing America. According to a recent poll from YouGov, Trump enjoys a measurable lead among Republican voters who go to church at least once a month, where he is at 31 percent, with Ted Cruz second at 25 percent. But Trump has an even larger lead among those who go to church less often or never, where he leads 40-16. This might explain why Trump felt the need to give a speech at Liberty University, where he could secure his small but crucial lead among churchgoers. Ultimately, though, it remains unclear who will win this war to be the political leader of evangelical Christianity. The Iowa caucus will be the first major battle in the fateful struggle.