Sometimes graphs convey a message more powerfully than words. University of Wisconsin-Madison political scientist Charles Franklin recently posted this plot of the “most important problem”–comparing the economy to the Iraq war. The visual representation of CBS News survey data is pretty dramatic. Both issues bumped along in tandem until 2006, when the war in Iraq became the dominant issue by a wide margin. In 2007, as the situation in Iraq improved, the number of Americans considering the war the most important issue declined. Yet in 2008, opinion shifted again. The number considering the war the most critical concern continued to ease, but when the economy slowed and the credit crunch emerged, the number of people choosing the economy as the most important problem shot up sharply.