The Presidential race is boiling down to one dominant issue: which party's policies will do more to help the financially stressed American middle class. President Obama's campaign theme is that Mitt Romney and the Republicans cater to the rich, while Mr. Obama cares about struggling families.

He may care, but he sure hasn't done much for them. New income data from the Census Bureau, tabulated by former Census income specialists at the nonpartisan economic consulting firm Sentier Research, reveal that the three-and-a-half years...