The following is part of a lengthy quote of a Walter Mead essay in Foreign Affairs (behind paywall) posted by John Ellis here. What makes this 2017 essay interesting is Mead's identification of Trump voters as Jacksonian populists.
For Jacksonians — who formed the core of Trump’s passionately supportive base — the United States is not a political entity created and defined by a set of intellectual propositions rooted in the Enlightenment and oriented toward the fulfillment of a universal mission. Rather, it is the nation-state of the American people, and its chief business lies at home.Jacksonians see American exceptionalism not as a function of the universal appeal of American ideas, or even as a function of a unique American vocation to transform the world, but rather as rooted in the country’s singular commitment to the equality and dignity of individual American citizens. The role of the U.S. government, Jacksonians believe, is to fulfill the country’s destiny by looking after the physical security and economic well-being of the American people in their national home — and to do that while interfering as little as possible with the individual freedom that makes the country unique.Jacksonian populism is only intermittently concerned with foreign policy, and indeed it is only intermittently engaged with politics more generally.
Ellis believes this explains Trump's peculiar hold on Republican voters, which hold seems impervious to external attacks. The whole Ellis essay is worth your time.