Those Earning Less than $25k / year give away almost twice as much as those earning more than $75 k / year
"...Lower-income people were more generous, charitable, trusting and helpful to others than were those with more wealth. They were more attuned to the needs of others and more committed generally to the values of egalitarianism.
“Upper class” people, on the other hand, clung to values that “prioritized their own need.” And, he told me this week, “wealth seems to buffer people from attending to the needs of others.” Empathy and compassion appeared to be the key ingredients in the greater generosity of those with lower incomes. And these two traits proved to be in increasingly short supply as people moved up the income spectrum. "
http://www.nytimes.com/2010/08/22/magazine/22FOB-wwln-t.html?_r=1Old Major's point fits in with this -- the red states are poorer states.
I suspect that a major share of these contributions from poorer people are given to their church.