The gap between what the rich and poor earn has been growing nationwide for four decades. The lowest 10 percent of wage earners nationwide were making no more than $7.70 an hour in 1973. That grew by just 4.5 percent, to $8.05, by 2009, according to the Economic Policy Institute, a D.C.-based think tank that focuses on the economic condition of low-and middle-income Americans.

Meanwhile, at the other end of the economic spectrum, the top 5 percent of earners made at least $35.37 an hour in 1973 compared with $48.08 in 2009 — an increase of 36 percent.