Of all the developments that have come along with Donald Trump’s capture of the Republican Party, few have been as unexpected as his robust support among conservative white evangelicals. What caused these socially conservative voters to embrace a candidate who built his brand on values so strikingly dissimilar from theirs? Why have many evangelicals gone so far as to actually uphold Trump’s values as a virtue in our current political moment?

I come to the question both as a political scientist and as a friendly observer of, and by some definitions, a participant in, the world of conservative white evangelicalism, who also did not vote for Trump and remains deeply Trump-skeptical. As a political scientist, I think it’s important to try and explain this recent evangelical political behavior in the context of broader questions about our current political moment, and religion and politics. As a friendly observer of conservative evangelicalism, who thinks categorical support for Trump is both unwise and harmful for evangelicals in the long term, I think it’s even more important to understand the reasons for that support. After all, understanding why it happened is the first necessary step to persuade evangelicals that it’s ultimately self-defeating. So, as a political scientist and a friendly observer/participant, I’d like to offer a theory: Donald Trump appeared at a time during which many evangelicals’ rising expectations had turned, rather rapidly, into existential fear. Trump was uniquely positioned to exploit that moment and win over evangelicals. Yet while that support is very real, I also think it is shallower and more conditional than it appears.

There exists within the religious right a tension between an expansionist view of transforming and redeeming politics, and a valid concern that religion and religious arguments will be pushed out of the public square altogether. Both of these ideas have existed in American Protestantism since Puritan times, but their modern expressions in conservative white evangelical politics can be traced to two very different American historical experiences. From about 1880 to 1920, evangelicals had a profound impact on both foreign and domestic policy, successfully advocating temperance, women’s suffrage, and laws against prostitution at home, and protection of Christian minorities, opposition to forced prostitution, and aid for victims of famine abroad. However, splits began to emerge in American Christianity over the continuing relevance of a number of doctrines. Those on the conservative side of the argument became known as the fundamentalists. In the 1920s, particularly after the Scopes Monkey trial, they were publicly pilloried as anti-intellectual for their opposition to evolution. The fundamentalists retreated from politics, built parallel institutions, occasionally emerged to show their support for Israel and opposition to communism, but largely remained politically disengaged. All of this changed in the 1970s, when a more self-confident evangelical movement emerged as a major player in the new right. Still, the conflicting impulses to bring the country back to God on one hand, and protect their right to access the public square from a hostile secular elite on the other, remained, and shaped the movement in future decades.

If we fast-forward to the mid-2000s, it’s clear that the more assertive and optimistic focus on “bringing the country back to God” was ascendant, and George W. Bush was about as natural a vehicle for this optimistic evangelical vision as possible. Statewide referenda in support of traditional marriage passed in even fairly blue states, evangelicals were deeply simpatico with Bush’s vision of compassionate conservatism at home and abroad, and Democrats, after 2004, began focusing on the need to win over voters in Middle America. Even as late as 2008, Barack Obama was telling interviewers that “I believe marriage is between a man and a woman” and displaying a degree of friendship with Rick Warren, one of the most popular mega-church pastors of the decade.

By 2015, all that had changed. No event exemplified that more clearly than Obergefell v. Hodges, which made gay marriage the law of the land. Before Obergefell, evangelicals generally thought they were “winning” the fight against gay marriage. They took comfort in the results of statewide referenda and largely missed the broader trend that millennials were moving left on the issue far and fast. The argument can certainly be made that they should have seen that shift coming. More than any other generation, millennials have grown up experiencing the full effect of no-fault divorce. The sheer ubiquity of divorce among their parents’ generation was going to work against any argument about reserving marriage exclusively for heterosexuals. Also, millennials were much more likely to know, and have had positive experiences with, LGBT people their own age. The idea that gay marriage represented an existential threat to the sanctity of marriage, while no-fault divorce did not, was unlikely to pass their smell test.

Despite those bright warning signs, Obergefell came as a huge shock to conservative evangelicals. They’d rapidly gone from certainty that they were winning big cultural fights to a very real fear that their views on marriage would be regarded as proof of bigotry. Given that the Obama administration regarded forcing nuns to provide contraception as a moral imperative, this fear was, perhaps, not totally groundless. Bluntly put, many evangelicals panicked.

Existential fear’s impact on political behavior is something political scientists have studied extensively. One of the primary drivers of this type of fear they’ve identified is when rising expectations about the future are dashed. In essence, this explains what happened to evangelicals, just as it explains the role declining trade between Britain and Germany may have played in World War I. And, as in war, pretty much the first thing a political movement does when faced with existential fear is to look for allies: the tougher, stronger, and scarier, the better.

Counterintuitively, the fact that Trump is bellicose, bombastic, insulting, and lives according to a code at odds with evangelicals’ beliefs actually made him more attractive as an ally, not less. “Evangelical nice” is a real thing, and like all good satirical characters, there’s a solid core of truth in The Simpsons’ depiction of Ned Flanders. That made evangelicals unlikely to see one of their own as capable of defeating an existential threat. But Trump embodied the opposite values, and he seemed determined to fight the people they were fighting.

It’s important to note one caveat in this story. If we disaggregate the polling data on white evangelicals from the 2016 primary to look at regular church attendance, rather than evangelical self-identification, it becomes clear that those who regularly attended church were less likely to support Trump than those who self-identified as evangelical but were not regular attenders. In his newly published book Alienated America, Tim Carney makes a compelling case that these regular churchgoers were less receptive to Trump’s broader message of social isolation and the death of the American dream. Existential fear, in other words, was less all-encompassing for regular attenders because they have more social connection. This analysis is almost certainly correct, but it’s important to note that most of these regular attenders came home to Trump in the end—and have, with some exceptions, generally supported him since. I believe the existential fear I describe remains the most helpful explanation of this political behavior even for these regular-attending latecomers, though Carney’s argument may imply that the attitude gap between regular vs. irregular attenders among self-identified evangelicals may persist in ways that are relevant to a 2020 primary challenge.

By accident or design, Trump did two things after winning the nomination that firmly consolidated evangelical support. First, he had the Federalist Society produce the list from which he would pick judges to the Supreme Court, and the lower courts. Second, he picked Mike Pence as his vice president. Though he’s despised by social progressives for numerous reasons, Pence’s bland, Midwestern style and self-evident social conservatism were reassuring to evangelicals in ways Trump could never be.

That much, at least, was transactional. But then, Trump won. And in so doing, he decreased the existential fear, thereby further justifying the alliance. And so he obtained an immense amount of good will among evangelicals, to the point that many of his most ardent supporters in that community see an attack on him as a proxy attack on them, their values, and their right to participate in the political process without leaving their faith at the door.

In the long run, of course, the evangelical alliance with Trump is almost certain to do more harm than good. Trump’s administration has certainly used executive action to follow through on some evangelical priorities related to abortion and religious freedom, and has appointed one, maybe two, reliably conservative Supreme Court justices. On the other hand, he’s also alienated millennials, ethnic minority voters, and college-educated suburbanites, and this alienation is making evangelicals and their positions more unpopular by proxy. It also doesn’t particularly help that, while past evangelical efforts on religious freedom (such as the 1993 Religious Freedom Restoration Act and 1998 International Religious Freedom Act) were explicitly designed to apply to Christians and non-Christians alike, Trump’s flirtation with things like Muslim bans undermines this universal argument in significant ways. Critics of broad religious freedom protections argue that they amount to “Christian special pleading”; it’s not a particularly good idea for evangelicals to condone any of Trump’s actions that give support to that argument.

There are broader problems with the alliance between Trump and conservative evangelicals—problems that impact not only the particular concerns of that religious group, but perhaps American politics in general. Trump is now inextricably associated with a kind of white ethnic populism that has been marginal, at best, in American politics before. American counterparts of figures like Jean-Marie LePen, or groups like the British National Party, had much less power and influence here than they did in Europe. I suspect that the rise of the religious right in America played no small role in this difference. A lot of the ethnic populist movements in Europe first gained traction roughly around the same time as the emergence of the religious right in America.

The United States is also significantly more religious than European countries, so a populism infused by religion, and not ethnicity, had more room to grow here. While the religious right was never great at winning over non-white voters who lean more socially conservative, it actively and persistently tried to do so. The movement’s rhetoric often trumpeted broad support within those minority communities on issues like abortion, school choice, and traditional marriage. This required at least paying lip service to ethnically inclusive politics—which, in turn, made the emergence of a full-throated white ethnic populism much more difficult. But in recent years, evangelicals became less interested in reaching out than in hunkering down and accepting any allies they could find. If, in fact, the religious right did play a role in inoculating America against the kind of ethno-nationalism on display in Europe, acceptance of a more ethnically oriented populism among evangelicals, which could result from their attachment to Trump, would be a particularly worrisome trend.

Bad as these developments look, there may be scattered signs of cautious optimism. First, the conservative age gap vis-a-vis Trump is, if anything, more pronounced among conservative evangelicals. Unsurprisingly, younger evangelicals were caught less off guard by Obergefell. Whatever their religious beliefs on traditional marriage, they were more realistic about the likely inevitability of same-sex marriage at some point in some form. So fear never set in as strongly, and even those who support Trump tend to be a good bit more transactional.

Indeed, strong anecdotal evidence suggests that conservative evangelical women under the age of 45 really don’t like him, even if most of them will never take that dislike far enough to vote for a pro-choice Democrat. (To my knowledge, no pollster has really tried to quantify the degree and intensity of this dislike, but it’s a project in which Trump-skeptical conservatives ought to have some interest.) My personal belief is that this demographic, what I’d broadly describe as socially conservative millennial moms, are ready to jump ship to just about any pro-life Republican at the first opportunity. If that’s true, it’s good news for those interested in a primary challenge to Trump. In and of themselves, they probably aren’t a big enough demographic to swing a primary, but as just about any pastor could tell you, don’t estimate the passion, organization, and grassroots influence that constituency could bring to such a primary challenge.

Second, I think there’s reason to hope the existential fear has receded. We’re a good bit further away from Obergefell, and in hindsight, Justice Kennedy’s statement that the rights of people with sincere religious objections to same-sex marriage must be taken into account looks to have been more than the platitude many evangelicals assumed it was. It’s significant that Kennedy actually cited Obergefell in his ruling on the Masterpiece Cakeshop case, specifically to argue that Colorado had not given due consideration to Jack Phillips’ religious beliefs. While it wasn’t the sweeping victory for religious freedom protections some were expecting, it did strongly affirm the right to bring such religious objections to the table in a serious way by a nice 7 to 2 margin. Such post-Obergefell precedents may dispel the fear that all is lost.

If that is the case, then a surprising number of evangelicals may be sympathetic to a conservative primary challenge that rejects Trump. Evangelicals are just as likely as anyone to feel a degree of burnout from the constant politicized spin-cycle of the past few years. And ironically, the fear they felt in 2015 has been mirrored by their most zealous opponents, precisely on the same grounds of rising expectations denied. Maybe the best message, for both sides, is a recognition that permanent culture war victories are almost impossible to win in a country this divided—and so what is needed is a just and lasting peace based on freedom, pluralism, and a modicum of respect for the sincere beliefs of those with whom we disagree. Such a pluralistic understanding would, at a minimum, provide evangelicals space to bring their sincere religious beliefs into the public arena where they can contest, compete, and compromise with those of every other creed, and none at all.

Fear will never get evangelicals there, and so Trump is ultimately a dead end. Freedom, on the other hand, just might.