Last December, teachers at Acero Schools in Chicago initiated the first major strike at a charter school network, capping off a year of teacher strikes across the country, from West Virginia to Oklahoma to Los Angeles. The charter school angle made the Acero strike noteworthy, and many media outlets were quick to note that it might be a harbinger of future unrest. The Chicago Tribune termed the strike a “warning to all charter operators.” USA Today said it could “portend more to come.”

These predictions weren’t as novel as they might seem. Indeed, the “teacher unions are coming for charters” narrative has been unfurled before. In 2015, the Wall Street Journal predicted that increased charter school organizing in Los Angeles “could have nationwide repercussions,” while the American Prospect proclaimed “more and more charter teachers are wanting to unionize.” A decade ago, in 2009, the same refrain was in evidence: Unions’ organizing of charters “shows signs of becoming a wave,” wrote Education Week. In short, for a decade or more, the notion that teachers unions are descending on charter schools has been a recurring theme.