*Spending totals for the Obama campaign are since 2009. The campaign had $81.7 million in cash on hand at the end of 2011.

Another type of group bringing in millions in contributions is the nonprofit 501(c)4. These groups can raise unlimited funds and run ads or donate to super PACs, as long as more than half of their activities are not considered political. They do not have to report their donors or balance sheets to the Federal Election Commission, but some chose to release overall contribution amounts: