But a year into a second Trump term, those “Trumpy intellectuals” are wielding palpable influence, even if it has been obscured by President Trump’s total lack of interest in the world of ideas. As Field explains in her fascinating and important new book, “Furious Minds,” what’s notable is how swiftly some esoteric theories have helped to radicalize the MAGA movement.

During the early 1960s, the historian Richard Hofstadter described anti-intellectualism as a phenomenon that was more pronounced on the far right. Field would mostly agree. In the United States, she says, conservative intellectuals were once largely an ameliorating force, acting as a “brake and restraint” on some of the right’s uglier impulses (bigotry, misogyny). Now, bizarre, “galaxy-brained” ideas that used to be the arcane obsessions of nerdy young men and buttoned-up tenured professors have become “an engine and accelerant for extremism.” Field borrows a vivid analogy from the Christianity scholar Matthew Taylor’s book “The Violent Take It by Force”: The fringe has become the rug.

Having written extensively about the New Right for outlets like The New Republic and The Bulwark, Field knows her subject well. She also has a personal connection to the material. She is a political theorist who studied with professors inspired by the 20th-century political philosopher Leo Strauss — a totemic figure among conservative thinkers for his embrace of the ancients and his refusal of moral relativism.

“I am not a conservative,” Field writes, “and never have been.” But she understands how Strauss’s teachings — especially his emphasis on decoding texts for secret meanings, a practice that can resemble conspiratorial thinking — have been weaponized by a generation of scholars who dislike the fact that the United States is a pluralist country. Strauss once described himself as a “friend of liberal democracy” and a teacher of “moderation.” Field writes about an intellectual movement that vehemently rejects both.

Field divides the figures in “Furious Minds” into three main groups: the “Claremonters,” who are associated with the Claremont Institute in California and “idolize the American founding”; the “Postliberals,” who want to curb individual rights in favor of what they vaguely define as “the common good”; and the “National Conservatives,” who endorse a homogenous nation-state and often embrace elements of Christian nationalism. Field also identifies another, more amorphous, group as part of this New Right: a “Hard Right Underbelly” that draws from (and fuels) the other three. Figures in this last group adopt aggressively silly nicknames like “Raw Egg Nationalist” (who has a Ph.D. from Oxford) and “Bronze Age Pervert” (who has a Ph.D. from Yale). They are extremely online and promote a hypermasculinist aesthetic; some of them, she notes, are openly racist and fascist.

What all these groups share is a hatred of liberalism — defined not as a partisan political ideology that is left-wing (though they hate that too), but as a system of government that values individualism and pluralism. Postliberals like Patrick Deneen, a political theorist whom Field credits with “the most palatable, sanitized version of Trumpy populism that one is likely to encounter,” started out by criticizing a liberal establishment composed of mainstream centrists in both parties.