Imagine, for a moment, how difficult it would have been to land a man on the moon if half of the U.S. Congress had believed that the sun revolved around the earth. Or consider how the War in the Pacific might have progressed if half of Congress had still thought the world was flat. Or whether polio would have been eradicated if half of Congress insisted that the best cure was bleeding using leeches. Unfortunately, this was the situation the United States in January 2009, when Barack Obama assumed the presidency. The nation was trying to climb out of the deepest economic hole since the Great Depression, but the Republican Party had about as scientific an approach to the economy as medieval alchemists did to the periodic table.