Donald Trump talks to the press after the CNN Republican presidential debate on Tuesday in Las Vegas.AP Photo/Mark J. Terrill

This article is from the archive of our partner National Journal

LAS VEGAS—The exchanges that drew the most attention in this week’s crisp and revealing Republican presidential debate featured Marco Rubio against Ted Cruz, Jeb Bush against Donald Trump, and the entire Republican field against President Obama’s national security record.

But none of those exchanges may influence the Republican Party’s future as much as another line of argument the debate dramatically sharpened: the case from several of the contenders against the foreign policy legacy of George W. Bush and even Ronald Reagan.

Some of that critique came from a familiar place: the libertarian skepticism of engagement abroad and aggressive law enforcement at home expressed by Rand Paul. More telling was the bristling but insular vision of America’s role in the world presented most comprehensively by Trump and largely reinforced by Cruz.

That approach braids skepticism of foreign military engagement, hostility to immigration, and resistance to free trade—what opponents call isolationism, nativism, and protectionism.

The embrace of these arguments by the two candidates now leading in national polls is both a challenge to the outward-looking internationalism that has long dominated the GOP, and another reflection of how the party’s increasing reliance on working-class white voters is destabilizing its internal debates.

For decades, most Republican leaders have taken the opposite views, supporting a robust American role abroad, expansive immigration, and free trade. In recent decades, that internationalist Republican consensus was most ardently advanced by Reagan and George W. Bush, each of whom backed legalization for undocumented immigrants, expanded trade, and a vibrant American role in leading other nations toward greater freedom.

Widespread disillusionment over Bush’s efforts to bring democracy to Afghanistan and Iraq at the point of an American gun cracked that consensus inside the GOP after he left office.

The first volleys came from libertarians such as Paul, who called for abandoning Bush’s recipe of aggressive international military intervention and heightened domestic surveillance. But Republican receptivity to the libertarian argument against an overreaching national security state has eroded amid growing concern over ISIS and terrorism. That receding tide is one reason Paul’s presidential campaign has sputtered.

But the libertarian retreat hasn’t restored the dominance of the internationalist consensus, especially in the idealistic, democracy-crusading form that the second President Bush embraced. Instead, Trump, joined on most issues by Cruz, has revived a strain of conservative “defensive nationalism” that traces back through Patrick Buchanan’s 1990s presidential campaigns to the heartland isolationists of the 1930s (whose rallying cry Cruz channeled on Tuesday when he said he represented an “America First foreign policy”).

Across the terrain of international engagement, immigration, and trade, Trump presents an agenda that is muscular and belligerent but ultimately defensive. Trump’s worldview rests on the belief that America needs walls, both literal and metaphorical, to protect it from a duplicitous and dangerous world. That defiant but dark perspective unifies his call to build a giant barrier across the Mexican border, temporarily ban Muslim visitors, impose “a pause” on legal immigration, and reject free trade deals. It also infused the powerful indictment he delivered at the debate of the Middle East interventions by Bush and Obama.

“In my opinion, we've spent $4 trillion trying to topple various people that frankly, if they were there and if we could've spent that $4 trillion … to fix our roads, our bridges, and all of the other problems … we would've been a lot better off,” Trump declared. “The people that have been killed … and for what? It's not like we had victory.”

As Carly Fiorina quickly observed, Trump there sounded like a Democrat. But his security vision decisively departs from the Democrats’ in supporting an unrestrained bombing campaign against ISIS, intrusive surveillance at home (including at mosques), and, of course, in portraying both undocumented Mexicans and American Muslims as potential security threats.

Cruz started in the Senate trying to bridge the GOP’s libertarian and internationalist strains. Some of that survives in his opposition to expansive government-surveillance powers. But mostly Cruz has drifted toward a Trump-like defensive nationalism: He’s promised massive bombing against ISIS while rejecting other intervention in the Syrian civil war, and abandoned his earlier support for both free trade and legalizing undocumented immigrants.

While Sen. Lindsey Graham forcefully defended the internationalist legacy in Tuesday’s undercard debate (even declaring, “I miss George W. Bush”), neither Rubio nor Jeb Bush, the leading top-tier internationalists, articulated that perspective nearly as effectively in the main event. Their hesitation may reflect a larger debate coming from Republicans over how much to accommodate the insular sentiments Trump has crystallized within their coalition, particularly among the blue-collar whites underpinning his support.

Peter Wehner, a shrewd former George W. Bush aide, says Trump’s defensive nationalism “is a hostile invasion of traditional Republican and conservative views [and] all-out assault on Reagan-ism [that would] … destroy the party.” But Jonathan Last of the conservative Weekly Standard, a magazine that ordinarily champions Bush-style interventionism, wrote after the debate that Republicans must adapt “to the totally new coalition of voters” Trump has assembled “around a new set of nationalist ideas.”

Like everything else involving Trump, that adaptation may prove a wrenching process for the GOP’s political and intellectual leaders.

This article is from the archive of our partner National Journal.

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