Political leanings: GOP/Conservative

Spending target: $45 million

Americans for Prosperity was founded by David H. Koch of Koch Industries. Koch and his wife, Julia, are major GOP contributors: They have donated more than $2 million to federal candidates and party organizations since 1990, according to the nonpartisan Center for Responsive Politics. Koch also ran for vice president on the Libertarian Party ticket in 1980, and currently serves on the board of the Cato Institute, a libertarian think tank, according to his biography on the AFP website.

The group’s president is Tim Phillips, a Republican campaign strategist who helped organize tea party protests. Directors of the organization include Art Pope, a former North Carolina congressman, and James Miller, former chairman of the Federal Trade Commission and budget director under President Ronald Reagan.

AFP is registered under the IRS code as a 501(c)(4) — meaning it does not have to disclose its donors. The Wall Street Journal said "some of the group’s funding comes from" Koch. Donations to the group are not tax-deductible.

AFP is affiliated with the Americans for Prosperity Foundation, which operates from the same address and with the same president and senior staff. The foundation is a public charity registered under the IRS code as a 501(c)(3) — meaning that donations to it may be deducted from the donor’s taxable income. Its donors also need not be publicly disclosed. In late August, 2010 the New York Times reported that the Democratic Congressional Campaign Committee had filed a complaint with the IRS accusing the AFP Foundation of abusing its tax-deductible status by running TV ads that it claimed were inherently “political in nature.” The AFP called the complaint without merit, and said it had raised money from 70,000 individual donors, according to the Times.

AFP’s stated mission is to advocate for low taxes and limited government. While the group does not directly endorse candidates, AFP hosts rallies and airs radio and television ads in support of or against policies and positions taken by certain candidates. It ran TV ads against President Barack Obama’s health care legislation, including one on breast cancer that we found to be "very misleading." AFP also has advocated against the passage of energy legislation supported by the president.

The Washington Post reported that the group "plans to spend more than $45 million targeting more than 50 House districts and half a dozen Senate races in key battleground states."