American progressives like to remember the mid–20th century as a time when the only thing higher than a Cadillac’s tail fin was the top marginal tax rate (which, during the Eisenhower years peaked above 90 percent for the very rich). Uncle Sam took 90 cents on the dollar off the highest incomes, and—as any good Bernie Sanders devotee will remind you—the economy thrived.
Conservatives, however, often try to push back on this version of history, pointing out that those staggeringly high tax rates existed mostly on paper; relatively few Americans actually paid them. Recently, the Tax Foundation’s Scott Greenberg went so far as to argue that “taxes on the rich were not that much higher” in the 1950s than today. Between 1950 and 1959, he notes, the highest earning 1 percent of Americans paid an effective tax rate of 42 percent. By 2014, it was only down to 36.4 percent—a substantial but by no means astronomical decline.