"In the long run, we are all dead," John Maynard Keynes once quipped. An influential British economist, Keynes used the line to dodge the problematic long-term implications of his policy proposals. His analysis of the Great Depression redefined economics in the 1930s and asserted that increased government spending during a downturn could revive the economy.

President Barack Obama and congressional Democrats (very few of whom likely have read Keynes's 1936 book "The General Theory of Employment, Interest and Money") have dug...