"I was in search of a one-armed economist so that the guy could never make a statement and then say: 'On the other hand . . .' "
-- HARRY TRUMAN
Ronald Reagan was luckier. He discovered a passel of single-minded, if not exactly single-armed, economists who called themselves supply-siders. They promised Reagan that he could cut taxes, rebuild U.S. military might and reduce the budget deficit, all at the same time. While the President eagerly followed the script, the deficit forgot its lines. Instead of shrinking each year, it added $1.3 trillion to the U.S. national debt during Reagan's two...