After the conservative movement defeated immigration reform in Congress two years ago, transforming the issue from one of great promise for Marco Rubio to an enduring liability, the Florida senator realized he had a problem with the right. 

With his signature initiative destined to become one of the world’s largest stockpiles of scrap paper, Rubio returned to the movement orthodoxies that had propelled him to the U.S. Senate in the first place. In 2013, he joined a quixotic campaign, organized by his future presidential-primary rival Ted Cruz, to condition funding for the government on the elimination of the Affordable Care Act—a strategy that culminated in a politically calamitous, two-and-a-half week government shutdown. He coined the phrase “I’m not a scientist, man”—a segue de rigueur among conservative politicians who want to reject responsible environmental policy without challenging the scientific consensus around climate change outright. And, perhaps most important, he rededicated himself to a different subject matter—foreign affairs—and aligned himself with the neoconservative policies of Lindsey Graham, John McCain, and other Republicans enamored of violent foreign entanglements.

These lurches to the right were meant to occlude and atone for Rubio’s heretical flirtation with immigration reform. His hawkish foreign policy in particular was supposed to provide him a leg up with primary voters on Cruz, who is more suspicious of interventionist foreign policy. 

This was misguided thinking. And if Cruz has his way, Rubio’s alignment with the neoconservative right will look in hindsight as ill-considered and out of sync with conservative voters as his view that a champion of citizenship for unauthorized immigrants could win the Republican nomination.

To the extent that conventional wisdom is possible in a campaign this erratic, a consensus is emerging among political analysts that looks something like this:

1. Despite his large, and enduring polling lead, Donald Trump still can’t win the nomination; something, at some point, will happen to derail his campaign.

2. Cruz will be the main beneficiary of Trump’s demise.

3. The establishment will coalesce behind Rubio as a more palatable alternative to Cruz.

4. The race will consolidate into a bloody slugfest between Cruz and Rubio, with Rubio enjoying overwhelming support from party actors and Cruz from conservative activists. Rubio will have a difficult time convincing ideological voters that he’s more authentically conservative than Cruz, who will gladly cite his rival’s official endorsements as evidence that he’s been compromised by the establishment.

5. As suggested by Rubio’s attacks on Cruz’s vote to end the NSA’s bulk, warrantless collection of electronic metadata, foreign policy will be the one arena in which Cruz will prove vulnerable on the right.

If you assume that point one (the premise) is correct for the sake of argument, and Trump can’t win, everything that follows is extremely plausible. Except for point five.

The assumption that Rubio can outmaneuver Cruz on foreign policy is based on simplistic conceptions of both Cruz’s strategic thinking and of the normative preferences of Republican primary voters. In this rendering, Republican primary voters always conform to the views of movement conservatives; Cruz adopts the movement’s substantive and tactical positions on every issue, which leaves him fairly invulnerable to attack from the right; but foreign policy is the one arena in which he’s deviated from the plan. If Republican primary voters always demand adherence to conservative movement orthodoxy, it would follow that Cruz erred by not hewing to a maximally bellicose foreign policy.  

Rubio’s allies have clearly bought into this view—one Rubio-aligned group is on air in Iowa with an ad attacking Cruz from the right for being insufficiently tough on terrorism. 

But they are wrong. Cruz is highly attuned to the views and grievances that animate Republican voters, even when they are out of step with the right-intellectual consensus. One of these arenas, where the right-wing position on a left-right axis fails to neatly line up with Republican voter sentiment, is foreign policy. 

Though they share a desire to be tough on terrorism, grassroots conservatives, unlike many Washington hardliners, don’t want the U.S. mired in unbounded entanglements. Here, the rightmost position—Rubio-esque neoconservatism—is identified with the dreaded Washington establishment, while organic conservative preferences are reflected in broad support for less militarily adventurous candidates. Republican voters trust Donald Trump to fight terrorism more than any other candidate by a wide margin. On this score, his nearest rival, Jeb Bush, trails him 42-18. These voters consider anti-terrorism a priority but are uninterested in a return to the George W. Bush doctrine. It’s why Trump’s line about “bomb[ing] the shit/hell” out of ISIS is such a hit with his supporters—but those supporters would also rather Russia get bogged down in an ugly war than us.

It’s also why Cruz isn’t crouching against Rubio’s foreign-policy attacks, but counter-striking with a ferocity, and an approach, that will surprise the shapers of conventional wisdom.

In an interview this week with Bloomberg Politics, Cruz linked Rubio to both Clinton-ite and outright neoconservative foreign policy, neither of which is popular on the grassroots right. “Senator Rubio emphatically supported Hillary Clinton in toppling [Muammar] Qaddafi in Libya. I think that made no sense,” Cruz said. “Qaddafi was a bad man, he had a horrible human rights record. And yet ... he had become a significant ally in fighting radical Islamic terrorism. The terrorist attack that occurred in Benghazi was a direct result of that massive foreign policy blunder. … If you look at President Barack Obama and Hillary Clinton and for that matter some of the more aggressive Washington neo-cons, they have consistently misperceived the threat of radical Islamic terrorism and have advocated military adventurism that has had the effect of benefiting radical Islamic terrorists.” 

Cruz also frequently makes a direct appeal to paranoia by suggesting (tongue partially in cheek) that Rubio’s preferred warrantless surveillance policy allowed President Obama to listen in on their phone calls

Rubio is a wily campaigner and debater, and Cruz may well have vulnerabilities that Rubio sees and we don’t. But they’re unlikely to stem from any ground where Rubio had a better sense of the grassroots mindset than Cruz. That’s Cruz’s real specialty, and foreign policy is no exception.