That is the findings from a study done by the Washington Post (by no means a right wing shill paper...quite the opposite) on willingness to give support to Katrina victims based on their race.
In a nutshell, Dems were willing to give less amounts of money to blacks and other minorities than they were to whites. While Repubs gave the same amount regardless of color.
The author tries to hit Repubs as well by saying they were less generous. However I take issue with that b/c they were talking about government money. So, in other words, Dems were more generous with OPM, not their own. I'd be willing to bet any amount of money if you compared the personal donations, Repubs would blow Dems out the water.