This 80-year history of free-trade progress is now under threat from the global recession and Mr. Obama’s abdication of U.S. leadership. Labor’s antitrade views now dominate in the Democratic Congress and liberal think tanks. As ominous, protectionism is increasingly justified by Democratic economists on political grounds.

Paul Krugman, the chief economist for House Democrats, has endorsed a carbon tariff. And Clyde Prestowitz, who insisted in the 1980s that Japanese mercantilism would rule the world, went so far as to argue in the Financial Times last week that imposing tariffs on China would strike a blow for free trade. As economic logic, this compares to the argument that the way to reduce government health-care spending is to pass a new trillion-dollar entitlement.