Written works of history unavoidably reflect the concerns of the time of their writing. The era of Trump has made its mark on historical writing, from Rick Perlstein issuing revisions of his picture of conservatism to Yale historian Timothy Snyder, never shy of courting controversy, becoming a full-on hashtag-resistance intellectual with his portentous warnings of tyranny in the offing.

Naturally, the dynamics of the moment have had their impact on history books dealing with the relatively recent past. It’s always a dicey game for historians to approach the present, but as the twentieth century recedes, the last decades of it become relatively safe ground. Or, it would be safe, if this wasn’t the logical place for historians to look for a way to explain the rise of Trump. Explaining Trump is hard enough. The effort of trying to explain Trump while holding on to an establishment liberal worldview is enough to warp any history.

Princeton historians Kevin Kruse and Julian Zelizer frame Fault Lines, their history of the United States since 1974, as the history of America’s growing divides. It is part of a growing literature, mostly coming from the social sciences but including journalism and now history, that tries to situate the problem of Trump as the result of social divisions. These divisions run along many axes — race, religion, gender, wealth, so on — but the ultimate division this literature talks about is that between conservatives and liberals; between the proverbial red and blue America. These works echo a similar literature produced during the George W. Bush years, but with much more panicky overtones.