Via Lawrence Lessig, who looks at where campaign cash comes from:
A tiny number of Americans — .26 percent — give more than $200 to a congressional campaign. .05 percent give the maximum amount to any congressional candidate. .01 percent give more than $10,000 in any election cycle. And .000063 percent — 196 Americans — have given more than 80 percent of the super-PAC money spent in the presidential elections so far.