Two words: Illegal immigration.
You beat me to it. Deport the illegals and watch these numbers drop DRAMATICALLY.
Eliminate the past 10 years of rampant invasion from south of the border and the poverty rate would be half the current number.
I prefer to look at the "glass half full" numbers.
Home ownership at an all time high and wealth also at an all time high.
The income levels that define the so-called poverty rate in America would be affluent in the countries of origin.
Not to mention the indirect effect of the depression of wages at the low-end of the economic scale.