How can a foundation with limited funds leverage its social impact? That's a question that haunted Seattle philanthropists Tom and Sonya Campion, who finally arrived at an answer: engage in advocacy.

"We cannot buy enough housing to end homelessness nor can we purchase the remaining wilderness in need of protection," the couple says on their foundation Web site. "Public policy can have far more significant impacts than we could otherwise attain with foundation dollars."

The hitch, of course, is that foundations are prohibited from lobbying or other political activity.

So, to complement the work of their foundation, the couple in January launched the Campion Advocacy Fund, a social welfare organization enabled by Internal Revenue Code section 501(c)(4). Although the primary purpose of these tax-exempt organizations must be social welfare, they may engage in a certain amount of political activity. They are often created as the lobbying arm for a movement. Unlike PACs, they need not divulge their donors.

As a part of the process, the employees of the Campion Foundation—all four of them—became employees of the fund. These employees continue to make grants on behalf of the foundation, in effect loaning their services. But they also make grants on behalf of the c4, which can also make grants to other c4s as well as to political candidates and PACs. According to the Center for Responsive Politics, for example, the Campion Advocacy Fund donated $400,000 to the Senate Majority PAC in January.

"We wanted to be able to influence legislation and be able to say what we want to say," Campion Advocacy Fund CEO Lisa Jaguzny said. "Now we have all the tools in the toolbox [to accomplish our social mission.]"

Although it is rare for a foundation to have a related c4, the Campion Foundation is not alone. Others with related c4s include George Soros's Open Society foundations and the Solidago Foundation.

In a twist, the Seattle-based Marguerite Casey Foundation, which is dedicated to the empowerment of poor families, is launching Equal Voice Action, a c4 organization it has incubated. The c4 will share the foundation's mission, but it will be membership-based and led by families.

Whereas the Campion's fund has top-down philosophy, reflecting the Campions' aspirations with respect to certain legislative goals, Equal Voice Action will be bottom-up, reflecting the goals of its membership.

The foundation's modus operandi with respect to its grants is not to tell people what they have to do with their money, and that same attitude pertains to the new c4, according to Marguerite Casey President and CEO Luz Vega-Marquis. "We have no political agenda," she said. "Marguerite Casey believes that families, particularly poor families, if given the opportunity, will lead. Equal Voice Action will be their voice."