The explosive growth of SuperPACs, able to accept unlimited donations and in many cases to conceal their donors, has transformed campaign finance.
In 2012, according to the Center for Responsive Politics, secret donors put more than $310 million into campaigns for President and Congress. Millions more went into campaigns for state offices across the country.
Freedom Partners, a non-profit group linked to billionaire industrialists Charles and David Koch, raised and spent $250 million in the 2012 campaign. The money was funneled through other non-profit groups to conceal the original donors.
The Supreme Court has ruled that disclosure requirements are constitutional and provide important protections against corruption.