Teachers unions in Massachusetts have tried before to obscure their involvement in political races: The Boston Teachers Union (BTU), an affiliate of the American Federation of Teachers (AFT) led by Randi Weingarten, was criticized by the Boston Globe for a shady political scheme designed to elect BTU’s favored mayoral candidate.

Now, Massachusetts legislators are trying to curb this sort of behavior by requiring SuperPACs like the one used by BTU and AFT to report their donors more frequently and in text on television advertisements. Despite employing so-called “dark money” networks of their own (like BTU/AFT’s), teachers union leaders have been at the forefront of efforts to restrict the influence of these so-called “dark money” groups. Whether or not the Massachusetts rule is actually good policy, it stands to reason that the union should be supportive of this proposal.

But guess who isn’t happy about Massachusetts’ proposed rules: It’s a union! According to a Boston Globe report, The Massachusetts Teachers Association, the state’s National Education Association (NEA) affiliate, is lobbying to strip at least one disclosure provision from the bill citing “technical issues.” Uh huh. As the Globe notes, MTA recently created its own SuperPAC to support its favored candidates in state elections, and the group spent $2.75 million in 2010 to re-elect Democratic Gov. Deval Patrick.

That an NEA group would try to block rules designed to combat the hiding of donors until after the election isn’t terribly surprising: The national union’s Executive Director was recently appointed Chairman of the left-wing money clearinghouse Democracy Alliance’s board. Either way, MTA’s recent lobbying is yet another indication that unions’ purported opposition to money in politics applies only to money they aren’t spending themselves.