Commonwealth Court Judge Dan Pellegrini said a central issue is "how power is allocated in the commonwealth of Pennsylvania."
"What's before us today is generally, 'Who decides?'" Pellegrini told the full courtroom in Harrisburg at the start of oral arguments.
Pennsylvania is the only northeastern state that does not allow gay marriage or civil unions. A 1996 state law says a marriage must be between a man and a woman, and it says same-sex marriages performed elsewhere cannot be recognized in Pennsylvania.
D. Bruce Hanes, the elected register of wills in Montgomery County, defied the ban in late July by issuing licenses to same-sex couples, as part of his duties as the orphan's court clerk. His action followed the U.S. Supreme Court's decision to throw out part of the federal Defense of Marriage Act, and a statement by state Attorney General Kathleen Kane that the same-sex marriage ban was unconstitutional.
The state Health Department, which is seeking a court order to stop Hanes, said it must ensure that marriage registrations are "uniformly and thoroughly enforced throughout the state." It said his actions have interfered with the proper performance of its powers, duties and responsibilities.
"He is issuing marriage licenses that the law clearly does not allow," said Greg Dunlap, representing the Health Department. "The Department of Health has an interest in the integrity of the record keeping system."
By the close of business Tuesday, Hanes had issued 164 licenses.
Pellegrini said he was not weighing the constitutionality of the same-sex marriage ban. But questions about its constitutionality arose repeatedly, and Pellegrini said he was concerned about the potential effect of his ruling on various levels of government.
The lawyers discussed how a sheriff might decide it was unconstitutional to deny gun permits to felons, or a zoning officer might think setback property line rules are an unconstitutional taking of private property.
"There's a lot of constitutional officers in this commonwealth," Pellegrini said.
The judge has to determine if the Health Department has legal standing to pursue what's known as a mandamus action to force a government official to follow the law. He also has to decide if Hanes qualifies as a judicial officer; if he does, the state Supreme Court may have exclusive jurisdiction.
Pellegrini allowed a lawyer for some of the people who have received licenses to participate in the argument. Afterward, one couple said they were not sure what to make of the session.
Kevin Taylor, of Havertown, who got a license from Hanes on the second day they were available, said seeking to intervene in the Department of Health case may be just the start of his legal efforts.
"We'll probably continue to sign onto lawsuits until this is resolved," Taylor said.