After the Paris attack, conventional wisdom held that Republican voters would finally turn away from political outsiders and reward candidates representing sobriety and experience. No one stopped to consider that, actually, voters might be drawn to the guy who memorably said of ISIS that he would “bomb the [expletive] out of them.”

Not only has Donald Trump not been hurt by Paris, he has bumped up in the aftermath (Ben Carson, on the other hand, has indeed dropped). The cliche about Trump is that he’s defying the laws of political gravity. If Trump is cutting against the contemporary political grain — certainly, no one else could get away with being as routinely careless and insulting in his statements — he is also tapping into one of America’s deepest cultural and political wellsprings.

In large part, Donald Trump is a Jacksonian, the tradition originally associated with the Scotch-Irish heritage in America and best represented historically by the tough old bird himself, Andrew Jackson. Old Hickory might be mystified that a celebrity New York billionaire is holding up his banner (but, then again, Jackson himself was a rich planter). Trump is nonetheless a powerful voice for Jacksonian attitudes.

Historian Walter Russell Mead once wrote a memorable essay on the Jacksonianism that, so many years later, serves as a very rough guide to the anti-PC and fiercely nationalistic populism of the 2016 Trump campaign.

Trump has trampled on almost every political piety, and gotten away with it, even when he has been factually wrong or had to backtrack. “The Jacksonian hero dares to say what the people feel and defies the entrenched elites,” Mead writes. “The hero may make mistakes, but he will command the unswerving loyalty of Jacksonian America so long as his heart is perceived to be in the right place.”

Trump condemns the political system, and everyone who has thrived in it. For Jacksonians, Mead writes: “Every administration will be corrupt; every Congress and legislature will be, to some extent, the plaything of lobbyists. Career politicians are inherently untrustworthy.”

Trump is obsessed with how other countries are taking advantage of us. He is tapping into the Jacksonian fear of, in Mead’s words, politicians “either by ineptitude or wickedness serving hostile foreign interests.”

Trump is hell on criminals and unwelcoming to illegal immigrants and Syrian refugees, reflecting what Mead characterizes as the Jacksonian’s “absolute and even brutal distinction drawn between the members of the community and outsiders.”

Trump never sweats the details. Jacksonians, according to Mead, believe “that while problems are complicated, solutions are simple.” In fact, the side in a public debate that “is endlessly telling you that the popular view isn’t sufficiently ‘sophisticated’ or ‘nuanced’ — that is the side that doesn’t want you to know what it is doing, and it is not to be trusted.”

Trump doesn’t believe in limited government. “Jacksonians believe that the government should do everything in its power to promote the well-being — political, moral, economic — of the folk community,” Mead writes. “Any means are permissible in the service of this end, as long as they do not violate the moral feelings or infringe on the freedoms that Jacksonians believe are essential in their daily lives.”

Trump isn’t ideologically consistent. The Jacksonian philosophy, Mead notes, “is an instinct rather than an ideology — a culturally shaped set of beliefs and emotions rather than a set of ideas.”

Finally, national honor is a paramount value for Jacksonians, a concern that can be heard in Trump’s signature promise to make America great again. He will out-bully and out-fox our adversaries and, as for ISIS, he will bomb and water-board it into submission.

It is tempting to see Donald Trump as something wholly new, the reality star who represents the merger of entertainment and popular culture. He is also something centuries old, the populist railing against a corrupt and ineffectual elite that will, through his chastisement, get the comeuppance it deserves.

Rich Lowry can be reached via e-mail: comments.lowry@nationalreview.com.