On the day that Alexandria Ocasio-Cortez accomplished her remarkable victory in the Democratic primary for New York’s 14th Congressional District seat, beating Joseph Crowley, the longtime incumbent, a new book arrived, as if by cosmic fiat, to help explain the emerging realignments of the political order.

“Squeezed: Why Our Families Can’t Afford America” examines the deteriorating fortunes of the middle-class — the teachers who sustain themselves with second jobs as Uber drivers; the young adjunct professors on food stamps; the unemployed 50-year-olds with few prospects; the junior lawyers far from the Wall Street partner track, carrying heavy student debt, whose work is already being automated.

In the book, Alissa Quart illustrates how life in a once-secure stratum has come to resemble the endlessly anxious existence of those in the rungs below. Bolstering the argument, as it happens, is new data from the federal Department of Housing and Urban Development, released this week, indicating that in three counties in the San Francisco Bay Area, where housing costs are famously astronomical, families earning $117,000 a year would now qualify as low-income, making them eligible for subsidized housing.

If you live in a place where a master’s degree won’t permit you a lifestyle that looks much different from an office clerk’s — if, in fact, it means you moonlight in a cubicle doing something you despise and eating lentils for dinner in the Rubbermaid TakeAlongs you brought from home — it follows that you will be less likely to think of yourself as a member of the privileged elite to which you have been told you belong and more inclined to find affinity with the broadening numbers of the more obviously oppressed, and vote accordingly.