The simple passage of time explains a lot. Millions of Millennials and Gen Zers were never exposed to the threats of the Soviet Union; they did not live through the fall of the Berlin Wall and the reforms of Mikhail Gorbachev; they do not remember the Mariel boatlift or the SALT treaties or the Cuban missile crisis. They grew up with the threat of terrorism predominant, with both Republican and Democratic administrations focusing on nonstate actors such as al-Qaeda and the Islamic State and violent dictatorships in the Middle East.

The right has also, inadvertently perhaps, softened the sting of the communist label by spending decades associating progressivism with socialism and socialism with communism, and arguing that free-market capitalism in a democratic framework is the only way to deliver prosperity. A “binary framing” dominated 20th-century politics, Lawrence Glickman, a historian at Cornell, told me, in which redistributive policies “might through the slippery slope lead to something dangerous, even totalitarianism.” The New Deal was often described in the 1930s and ’40s as a “wolf in sheep’s clothing” or a “Trojan horse,” he said.

Now that kind of argument sounds more like crying wolf. Facing yawning inequality, heavy debt burdens, obscene costs of living, and stagnant wages, young people have warmed up to redistributive politics.