A Pennsylvania state law that bars political committees from taking contributions from corporations or organizations, like labor unions, for political purposes is directly at odds with Citizens United, a Washington, D.C.-based “super PAC” argued in its challenge to the measure.

The General Majority PAC, a political organization registered under Section 527 of the Internal Revenue Code that advocates for Democratic candidates in state legislative races across the country, filed its challenge in federal court in Harrisburg, Pa., this week.