As Missouri legislators roam the state Capitol, they frequently run into familiar lobbyists. More and more, though, these lobbyists are working for groups financed by unfamiliar donors. In fact, their identity is secret.
Such groups are nonprofits officially known as 501C4s, a designation that refers to a provision of the IRS’ tax code. Since the U.S. Supreme Court ruling in 2010 known as “Citizens United,” these organizations can get involved in politics in favor or opposition of candidates, just like political action committees.