In the past few weeks — really, the past few years — a cottage industry has grown up on liberal websites and op-ed pages, in Facebook memes and political magazines, trying to make historical sense of the country’s spiraling rightward extremism.

Understandably, people are hungry for facts and ideas that can explain the current insanity. What you might call the magazine-reading class is feeling disoriented, I think. Like most of us, they live in a day-to-day world that seems, if anything, hyper-depoliticized: a world of Starbucks and smart phones and reality TV, in which expressions of political militancy are almost never heard. Crashing into this postindustrial idyll comes a national crisis engineered by wild-eyed insurgents quoting eighteenth-century philosophers. It seems to come out of nowhere.

The other day I got into an argument (yes, it was on the internet) about an article belonging to this cottage industry — though this particular article was a relatively sophisticated product. The piece, by the New Republic’s John Judis, along with this 2011 prequel he wrote during the last debt ceiling crisis, offers a historical explanation of how U.S. politics got to the point where the current government shutdown — “one of the worst crises in American history,” according to the headline — has become possible.