One reason that some non-interventionists had hope that the
Republican base was coming around on foreign policy was their widespread
opposition to intervention in Syria following the alleged Ghouta chemical
weapons attack by President Assad in 2013. We now know
with near certainty that that attack was a Turkish false flag designed to
drag the U.S. into the war on the side of the rebels, as non-interventionists
insisted all along, but that is for another essay. The attack appeared to
violate Obama's rhetorical "red line," and the U.S. seemed poised for war until
Russian President Vladimir Putin intervened and saved President Obama's bacon.
What happened to prevent a U.S. attack at the diplomatic level is interesting, but on the ground in the U.S. there was widespread resistance on the part of the Republican base and consequently Republican office holders to support a U.S. attack on Syria. The main Republican and "conservative" voices supporting U.S. intervention in 2013 were the interventionist ideologues who reliably support military intervention such as Sen. Lindsey Graham, Sen. John McCain, and pundit Bill Kristol. Much to the chagrin of non-interventionists, especially those of us who thought Trump's America first rhetoric represented a real change in direction on foreign policy, the GOP base is all onboard with Trump's airstrikes. (86% for Trump's intervention vs. 22% for Obama's potential intervention.)
It would be easy to view this as rank partisanship, and surely some of it is, but Jarrett Stepman offers an additional explanation for this dichotomy in an article at The National Interest entitled "Trump's America 'First Policy' Will Woo Jacksonians." Stepman's explanation rings true to me and accords with observations about the GOP base that I have previously made myself (see here, here, and here), although Stepman seems supportive of the strike while I most certainly am not.
Most of the GOP base's attitude toward foreign policy is what political scientist Walter Russell Mead has called "Jacksonian," after America's seventh president, Andrew Jackson.
They do not believe that the United States should go out in the world seeking monsters to destroy, but instead they view America's international relations through the prism of what is specifically in our self-interest"
Jackson believed, as many Jacksonian voters understand today, that for the United States to maintain peace the country must be feared and respected. Jacksonians are generally proponents of using overwhelming force once they have calculated that the nation and its interests are threatened, and they demand that American "honor" be upheld in foreign relations.
Daniel Larison at The American Conservative objects to Stepman's framing because he argues that Trump's strike on Syria was not in our self-interest. I believe Larison is correct, but what is in play here is the GOP base's perception of our self-interests, not reality. Larison's objection is really less a criticism of Stepman's argument and more a recognition of the weaknesses and limitations of Jacksonianism vis-a-vis Jeffersonian non-intervention.
The problem with Jacksonianism from a non-interventionist perspective is that it can approach Jeffersonianism if it narrowly defines our interests and narrowly perceives threats, or it can approach Wilsonianism if it broadly defines our interests and broadly perceives threats. I do believe it is true that the average rank and file Republican voter is not an ideological Wilsonian, but they do over define our interests and over perceive threats and thus support interventions that are not in our real interests. They must broadly defines both these things in order to perceive a small far off country like Syria that has not attacked us as a threat or a vital interest.
American Jacksonians have this broad view because they have embraced decades of catechization that the U.S. must of necessity play a greatly outsized role on the world stage, so they see our interests and threats from their viewpoint of our necessary role, not from the view of actual real threats to the homeland. To put it another way, American Jacksonians have incorporated an element of Wilsonianism into their baseline assumptions. This often quickly comes out when you challenge them about the literal threat posed by whatever the bad foreign country of the day is.It is this view of the U.S.'s role on the world stage that must be relentlessly challenged, but the Jeffersonians are not going away anytime soon so it is important to understand how they think and work with it. Mr. Stepman's article is a good starting point for this understanding. In the grand scheme of things, we can be thankful that they are at least better than the Utopian Wilsonians.