It's not unusual these days for Democratic politicians to voice support for same-sex marriage, but Treasurer Rob McCord is going a step further and joining in a lawsuit to topple Pennsylvania's law limiting matrimony to one man and one woman.

McCord, a candidate for his party's nomination for governor, filed a friend-of-the-court brief in the federal case Monday.

The case, filed by a lesbian couple who married in Massachusetts, argues that Pennsylvania’s refusal to recognize their union violates the U.S. constitution’s guarantee of equal protection under the law.

In his amicus brief, McCord brought the case to the practical level, describing the "pervasive  and discriminatory impact" faced by people in a same-sex relationship when it comes to inheritance, unclaimed property, the state's tuition savings program, retirement benefits and other matters under the purview of the treasurer's office.

"From a time in which states once enacted anti-miscegenation laws, imposing similar discriminatory effects, such laws have been deemed unconstitutional as depriving individuals of equal treatment under federal law," the brief concludes. "Pennsylvania's law is equally demeaning: its professed purposed is to remove the dignity and legal acknowledgement of marriage from a newly disfavored class – same sex couples."

The case is Palladino versus Corbett and Kane, pending in U.S. District Court in Philadelphia.