Bloomberg has an excellent story about the undisclosed political money spent by corporations and energy interests during 2010–made possible by the Supreme Court’s notorious Citizens United decision.
This quote jumped out at me:
The non-party organizations that don’t disclose their donors increased their spending to $133 million in 2010, compared with $875,000 during the previous off-year elections in 2006, according to the Center for Responsive Politics, and favored Republicans by a ratio of 10-to-1.
That is, the decision resulted in a 150x increase in spending among such groups. And the spending was 10x more likely to help the party that appointed all five Justices in the Citizens United majority.