The Times discusses the American Action Network in this story today, saying the group will be a conservative counterpart of the Center for American Progress.
Like the Center for American Progress, the tax-exempt American Action Network will be divided into separate units. The Action Forum, which will be the policy arm, is a 501(c)3 group, named for the tax code provision for charitable groups; it allows contributions to be tax deductible but restricts political activities.
The Action Network, which will advocate for policies and candidates, is a 501(c)4 organization. Contributions are not tax deductible, and the group can advocate for political causes.