As stated in the Americans for Prosperity’s December 31, 2009 audited statements, AFP is a 501 c 4 corporation under the Internal Revenue Code and is exempt from taxes.
Are contributions to a 501 c 4 corporation deductible: http://www.irs.gov/charities/nonprofits/article/0,,id=156411,00.html
Donations to Section 501(c)(4) Organizations
Contributions to civic leagues or other section 501(c)(4) organizations generally are not deductible as charitable contributions for federal income tax purposes. They may be deductible as trade or business expenses, if ordinary and necessary in the conduct of the taxpayer’s business. However, see Nondeductible Lobbying and Political Expenditures for more information. Also, the organization may be required to disclose that contributions are not deductible when it solicits contributions.
Donations to volunteer fire companies are deductible as charitable contributions on the donor’s federal income tax return, but only if made for exclusively public purposes. Similarly, contributions to certain war veterans organizations are deductible. If the contributions are deductible as charitable contributions, substantiation and disclosure requirements may apply.
Americans for Prosperity
Their website is: http://americansforprosperity.org/walker/ is running the following support commercial for Wisconsin Governor Walker.
The following is taken from the IRS Code: http://www.irs.gov/pub/irs-tege/eotopici03.pdf
Although the Service has been making an effort to refine and clarify this area, IRC 501(c)(4) remains in some degree a catch-all for presumptively beneficial non-profit organizations that resist classification under the other exempting provisions of the Code. Unfortunately, this condition exists because "social welfare" is inherently an abstruse concept that continues to defy precise definition.
The general concept, however, can be expressed as follows:
Organizations that promote social welfare should primarily promote the common good and general welfare of the people of the community as a whole.
An organization that primarily benefits a private group of citizens cannot qualify for IRC 501(c)(4) exempt statute
.Local associations of employees, the membership of which is limited to the employees of a designated person or persons in a particular municipality and the net earnings of which are devoted exclusively to charitable, educational, or recreational purposes.
The statutory terms disclose that IRC 501(c)(4) embraces two general classifications:
a. Social welfare organizations, and
b. Local associations of employees.
Statutory History
Effective September 14, 1995, organizations exempt under IRC 501(c)(4) may not allow any part of their net earnings to inure to the benefit of any private shareholder or individual.
Further, insiders and organization managers may be subject to the excise tax imposed by IRC 4958 if assets or services are provided to insiders for less than fair market value. Taxpayer Bill of Rights 2, Pub. L. No. 168, § 1311(a), 104th Cong. 2d Sess (1996), 110 Stat. 1452.
IRC 501…..
Feb. 1, John Kaufield, president of the Y’s board of directors, began working as its interim CEO — just days after Bill Holsker was terminated. 
