Matt Taibbi, a contributing editor for Rolling Stone magazine, is the author, most recently, of “Griftopia: A Story of Bankers, Politicians, and the Most Audacious Power Grab in American History.”

America never got over the ’60s. The deep social divisions that emerged during that decade remain, for the most part, the divisions that define modern American politics. The battle lines are still so painfully visible that 50 years after the beginning of the Vietnam War and the Free Speech Movement at the University of California, Berkeley, the presidential race this year will come down to a contest between a former community organizer pilloried for supposed ties to ’60s radicals and a former Stanford student who protested against campus antiwar demonstrations.

Moreover, the current culture war being played out between watchers of Fox News and readers of The Huffington Post is really the same old ’60s argument, pitting social conservatives’ unshakable faith in American exceptionalism against the progressive insistence that there’s something dark and violent at the core of American hegemony. These two sides have painstakingly constructed competing versions of recent American history, leaving us without even a common set of historical facts to debate.

It’s important to try to ignore all of this background when reading “Subversives,” the journalist Seth Rosenfeld’s electrifying examination of a newly declassified treasure trove of documents detailing our government’s campaign of surveillance of the Berkeley campus during the ’60s. Rosenfeld spent 30 years fighting to compel the government to release more than 300,000 pages of documents about the illegal spying program, an effort the F.B.I. spent almost a million dollars opposing....