Her economic illiteracy matters because she is the principal author of the Green New Deal, which has been endorsed by most of the leading Democratic candidates for president. From this unschooled mind has sprung the most ambitious plan for government intervention in the economy since Vladimir Ilyich Lenin’s train pulled into Petrograd’s Finland Station.

If Ocasio-Cortez doesn’t understand how tax subsidies work, how can she be trusted to plan the federal takeover of the health-care, energy and transportation sectors of our economy? Think she and her allies have any idea how to, as her now infamous talking points put it, upgrade or replace “every building in America” . . . or replace “every combustible-engine vehicle” . . . or connect every corner of America with high-speed rail . . . or replace all fossil-fuel energy with alternative energy sources — all in 10 years’ time? Apparently, they think we just have to find all the magic pots of cash the government is hiding.

When this kind of ignorance is driving policymaking in Washington, America is in profound danger.