Democrats are expanding their attacks against conservative groups who buy pro-GOP advertising, with the goal of forcing the revelation of the groups’ donors. Groups like MoveOn.org and Public Citizen are urging TV networks to ask whether the ads are being purchased with a legal source of funds while pushing the Justice Department and IRS to investigate the conservative groups’ donors. Democrats have charged that the U.S. Chamber of Commerce, as well as two groups backed by Karl Rove, are buying ads illegally with money from overseas. Conservatives deny those charges, and Rove and others on the right have fired back that MoveOn and unions are being hypocritical, because they don’t disclose their donors, either. But that charge is wrong. MoveOn is a federal PAC, and must disclose its funding as fully as a political candidate. Unions also face strict disclosure laws. After making such a charge on his morning talk show, Joe Scarborough retracted his claim, but Karl Rove has yet to do so.