A century ago, Britain was rocked by perhaps the most serious episode of class struggle it has ever known. Millions of workers joined the general strike of 1926, buoyed by hope that they could fend off attacks on the pay and conditions of coal miners and reverse efforts by bosses to claw back the gains organized labor made when workers were in urgent demand during World War I. They faced opposition from employers, Stanley Baldwin’s Conservative government, and a larger swath of the middle…