Sen. Sheldon Whitehouse, D-Rhode Island, has launched a campaign to reform what he calls the “fecklessness” of the U.S. Supreme Court’s rules requiring the disclosure of who is behind amicus curiae briefs filed with the court.

Last month Whitehouse sent a letter to Chief Justice John Roberts Jr. and Court Clerk Scott Harris, decrying “the court’s practice of routinely accepting amicus curiae briefs from special interest groups that fail to disclose their donors.”