The political rise of Donald Trump, first as a proponent of the “birther” conspiracy theory, then as a plausible presidential candidate, and now as the likely Republican nominee, will be seen as a grim episode in American history. It has revealed the dark, authoritarian core of large parts of the conservative movement, brought open bigotry back into the political mainstream in a way many believed had been relegated to our past, and raised serious questions among US allies—indeed, across the international community—about the quality of American democracy. But the Trump phenomenon has also revealed something important about the connection between the Republican-establishment policy community and the conservative grassroots—or more accurately, the lack of connection. This has been particularly stark when it comes to foreign policy, which, in the post-9/11 era, has been dominated by a vision of militaristic global hegemony espoused by its neoconservative faction.

In the days and weeks before the South Carolina primary, Trump seemed to delight in rejecting key elements of the neoconservative agenda. He accused the Bush administration of lying the United States into the Iraq War, which he called a “big fat mistake” that “destabilized the Middle East.” He mocked Jeb Bush’s contention that his brother George W. Bush had “kept us safe,” telling him,“The World Trade Center came down during your brother’s reign, remember that.” He pointedly refused to promise to “rip up” the Iran nuclear agreement once in office, as other candidates had. He also pledged to be “sort of a neutral guy” on the Israeli-Palestinian conflict in the hopes of brokering a peace deal. “I don’t want to say whose fault it is,” he said. “I don’t think it helps.”

After committing these heresies, Trump didn’t just win the South Carolina primary; he won among evangelicals, who have been long seen as a key grassroots constituency for the neocons’ hawkish agenda. It’s hard to say how much of a role Trump’s rejection of that agenda played in this victory, or subsequent ones, though polls have shown that national security is a top concern for GOP voters. At the very least, though, Trump’s success shows that a whole set of positions that Republican hawks have insisted for years are “non-negotiable” are, in fact, quite negotiable, and that a Republican candidate can reject those positions, even mock them, and still win decisively.

And it’s not just Trump. Even his closest competitor, Ted Cruz, who, while he traffics in the same highly problematic “clash of civilizations” rhetoric that animates much of neoconservative foreign policy, rejects the neocons’ preferred prescription of US-backed regime change, instead insisting that backing Middle East dictators is the best way to keep America safe from the threat of Islamist extremism.

Meanwhile, Marco Rubio, the neocons’ chosen candidate, saw his campaign finally collapse, despite the determination of Washington-based pundits to repeatedly resuscitate it. This is fitting, as Washington experts have always been the neocons’ primary constituency. But while they retain control of the commanding heights of the Washington policy-making apparatus, what the Trump phenomenon has revealed is how disconnected these views are from actual Republican voters. The question is whether Trump’s rise will finally force the reckoning that the neocons have been able to stave off for years.

Back in 2010, I published a piece in The Nation examining how the neocons had repositioned themselves in the wake of the Iraq debacle and the election of Barack Obama by amping up the fear-mongering on terrorism in order to raise the political costs for Obama’s attempt to shift US foreign policy in a different direction. The neocons have proven reasonably effective in recent years at channeling conservative popular grievances into political opposition to Obama’s agenda. What they clearly haven’t been able to do is channel it into durable support for their own.

Rather than undertake a serious appraisal of how the Iraq War had disproven their very specific claims about the capacity of American military power to shape outcomes, they peddled the face-saving fantasy that the 2007–08 troop surge had redeemed the war, and that Obama had squandered this splendid victory by withdrawing US forces in 2011. (In fact, he withdrew those forces according to a timetable agreed to by the Bush administration, in the face of overwhelming demand for US withdrawal by Iraqi politicians.) Rubio’s campaign slogan “A New American Century” was clearly intended to reference the Project for the New American Century, the 1990s-vintage letterhead organization that advocated energetically for the Iraq invasion. The fact that anyone in Rubio’s circle of advisers thought it a good idea to evoke the name of an organization closely associated with an overwhelmingly unpopular war signals a troubling detachment from reality; it’s the political equivalent of releasing “Even Newer Coke.”

The neocons successfully contained anti-interventionist sentiment in the GOP, personified mainly by Ron and then Rand Paul, neither of whom were ever able to challenge the neocons’ place in the GOP’s policy-making and media infrastructure. They worked hard to build relationships with the populist Tea Party movement in order to blunt its anti-interventionist bent. Though he started to make some headway, Rand Paul’s challenge to neocons crested in 2014, as the rise of ISIS—particularly the taking of Mosul and the beheading of two American journalists in late summer of that year—set off a wave of media-driven hysteria that the pro-interventionist neocons were ready, as always, to exploit in order to retake control of the debate. They soon settled on Rubio as their chosen candidate for 2016, while also grooming Iraq War veteran Tom Cotton as their new McCain.

But Trump threw a wrench into these plans. He represents a new and more formidable challenge than either Ron or Rand Paul: He’s great at capitalizing on the belligerent ultra-nationalism that the neocons have cultivated over the years, but has little use for their ideas, thank you very much, openly scoffing at their agenda of “benevolent global hegemony” while preaching a much more gut-level gospel of American strength unbound by any international norms whatsoever.

Like the Pauls, Trump has not seriously challenged the neocons’ control of the GOP’s elite institutions, at least not yet. But unlike them, he has been able to demonstrate how little those institutions might actually matter, at least when it comes to national political campaigns.

The focus on Trump also creates a convenient excuse for conservative elites to avoid acknowledging their own role in stoking the paranoia that he’s exploiting. In early March, a group of conservative foreign policy experts issued an open letter stating their opposition to Trump and declaring themselves “unable to support a Party ticket with Mr. Trump at its head.” But a number of the policy positions that ostensibly made Trump an unacceptable option were also held by Ted Cruz or Marco Rubio, or both.

The indignation over Trump’s bluster is a bit hard to take. Commenting on his March 3 debate performance, National Review’s Jonah Goldberg tweeted, “I cannot believe people watch Trump and see a strong man. I truly cannot understand it. I see a whiny insecure punk and bully.” Back in 2002, Goldberg justified his support for the Iraq invasion by citing pro-interventionist scholar Michael Ledeen’s view, which he characterizes as “every ten years or so, the United States needs to pick up some small crappy little country and throw it against the wall, just to show the world we mean business.” In mid-March, Cruz announced his team of foreign-policy advisers. Along with Ledeen, who represents its moderate wing, it includes anti-Muslim activist Frank Gaffney, who has claimed that the Bush and Obama administrations were infiltrated by Muslim agents, and suggested that Obama himself is one.

This isn’t exceptional in today’s GOP. Even Marco Rubio, the ostensibly “serious” candidate, got in on the paranoia game before he bowed out, claiming that Obama “has deliberately weakened America.” His robotic recitation that Obama “knows exactly what he’s doing” earned mockery, but it overshadowed the noxiousness of the actual claim: that the president of the United States is a knowing, intentional agent of America’s destruction. Back in 1965, William F. Buckley Jr. famously excommunicated the anti-Communist John Birch Society from the conservative movement for, among other things (including being insufficiently hawkish), their leader Robert Welch’s claim that President Dwight Eisenhower was a “dedicated, conscious agent of the Communist conspiracy.” These sorts of wild claims have now become an accepted part of the conservative mainstream, their proponents embraced by top candidates, or espoused by candidates themselves.

The inconvenient truth is that Trump has simply refined to its essence the style of discourse that the neocons helped develop. “When you establish that vaguely coherent bluster is the most important contribution a President can make on the foreign stage,” University of Kentucky professor Robert Farley recently tweeted, “then you shouldn’t really complain when someone comes along, drops the ‘vaguely coherent’ bit, and just keeps the bluster.” What Trump is exploiting is the fact that, while it’s unfortunately pretty easy to scare people about terrorism, none of the GOP’s own experts have been able to explain to the party’s voters how any of the policies they advocate have made their lives better.

“I believe that Trump is the result of the establishment’s ignoring public sentiment with respect to many things, but what I care about is foreign policy,” said Christopher Preble, vice president for defense and policy studies at the libertarian Cato Institute. “We’ve known about the gap between elite opinion and public opinion on foreign policy for a long time. The reason this hasn’t manifested itself is because they haven’t been given a choice in the elections.”

The hard part, Preble continued, “as an empirical matter, is that you rarely have foreign policy hermetically sealed from other issues. Trade and immigration is wrapped up in Trump’s appeal too. Some of us who believe in restrained foreign policy agree with more trade and immigration, so separating out what’s actually driving Trump’s success is hard. But people tend to conflate these issues.” While offering an analysis of Trump’s appeal, Preble made clear that he sees Trump’s protectionist agenda as a serious problem. “I don’t want to live in a country that shuts itself off,” he said, “but the foreign policy establishment says you have to do all of these things. It’s all or nothing. So the first guy that comes along that gives [voters] that choice, they’re gonna pick that guy.”

Some analysts express hope that the Trump phenomenon could spur a much-needed audit of deeply held assumptions about policy, foreign and otherwise. “Many things are driving Trump’s candidacy, including legitimate anger with the system and also some of our uglier impulses, but the reason that party elites’ warnings about Trump aren’t being heeded is that the average Republican voter thinks those elites have not done a competent job of managing the political system,” said Daveed Gartenstein-Ross, a conservative foreign-policy expert who has served as an informal adviser to the Rubio campaign. “It is almost axiomatic that there is legitimacy to those feelings. If Trump’s rise is to have a positive effect on national politics, it will be in forcing mainstream candidates to focus not just on the politics of their positions but also the efficacy; and in also making these candidates move away from sloganeering and explain why received wisdom should be trusted, and to jettison it if it cannot. The negatives of Trump’s rise may well massively dwarf these positives, but I believe there will be at least some oscillations in the direction that I described.”

It remains to be seen whether the neoconservative faction that has dominated conservative foreign-policy making for nearly two decades will ultimately be forced to reckon with its own failures, and what that reckoning will mean for the Republican Party, and for the conservative movement. Like much of the rest of the GOP establishment, many neocons have already started to frantically cluster around Ted Cruz in the hopes of averting a Trump nomination and maintaining their own relevance. (The fact that they would do this even though Cruz rejects the democracy-promotion agenda gives you an idea of how seriously neocons themselves take it.) It’s worth noting, though, that were Trump to win the November election (shudder), he’d likely have to reach out to the neoconservative bench to staff his administration. This could either create new opportunities for them to shape his agenda more to their liking, or alternatively it could see Trump using the power of the presidency to fundamentally reshape GOP foreign-policy making according to his vision, to the extent that he has one.

Yet another possibility is that the neocons will start to migrate back to the Democratic Party, which they exited in the 1970s in response to Vietnam-inspired anti-interventionism. That’s what earned their faction the “neo” prefix in the first place. As Nation contributor James Carden recently observed, there are signs that prominent neocons have started gravitating toward Hillary Clinton’s campaign. But the question is, Now that the neocons has been revealed as having no real grassroots to deliver, and that their actual constituency consists almost entirely of a handful of donors subsidizing a few dozen think tankers, journalists, and letterheads, why would Democrats want them back?