This may be our first comprehensive look at the muscle being put forth by well-funded interest groups after the Supreme Court loosened some campaign fundraising and spending rules.
- $18.4 million: American Crossroads and Crossroads GPS
- $15.5 million: The U.S. Chamber of Commerce
- $9.4 million: The AFL-CIO
- $7.7 million: American Future Fund
- $6.1 million: 60 Plus
Under the law, many of the 120 groups Public Citizen tracked are not required to, and do not, disclose information about their funders. "Of the highest-spending groups, only American Crossroads discloses any information about its funders," says Public Citizen, "its sister organization, Crossroads GPS, is a 501(c)(4) and so does not disclose the identities of its donors."
Another analysis, this one by the Sunlight Foundation, has found that for the first time, outside groups are spending more than political parties: 59 percent of independent expenditures" versus just 18 percent in 2006. That's almost triple.
The latest filings with the Federal Election Commission show that Republicans bested Democrats in direct contributions to candidates in top races in the past three months, but Democrats still have a bit more money left in the bank to spend.
Sharyl Attkisson is a CBS News Investigative Correspondent based in Washington. You can read more of her posts in Hotsheet here.