House Speaker Paul Ryan's ambitious tax overhaul relies on an import tax concept originally developed by a Berkeley economist who once advised Democratic presidential candidate John Kerry. Alan J. Auerbach is the director of the Robert D. Burch Center for Tax Policy and Public Finance at the University of California, Berkeley. He served as an economic counselor to Kerry during his 2004 presidential campaign. He also happens to be known as the godfather of "border adjustability," the linchpin of the tax reform plan that Ryan, a conservative Wisconsin Republican, is attempting to sell to the White House and push through...