"The train has left the station," said Jill Engle, a law professor at Pennsylvania State University. "This is going to be decided by some judicial body in Pennsylvania."
The state's ban is being challenged on the federal level by the American Civil Liberties Union, which filed a suit last month in U.S. District Court in Harrisburg.
Pennsylvania's marriage law restricts marriage to one man and one woman, and states that same-sex marriages performed in other states and countries "shall be void in this commonwealth."
In late July, D. Bruce Hanes, Montgomery County's register of wills, started to issue marriage licenses to same-sex couples. His defiance of state law began nearly a month after two U.S. Supreme Court rulings - one allowing same-sex couples to receive federal benefits, the other effectively leaving the legality of gay marriage up to the states.
Hanes so far has issued 62 marriage licenses to same-sex couples from across the state, including a couple Friday from Pittsburgh. Thirteen couples are known to have married, county officials said.
Last week, the state Department of Health filed a lawsuit asking Commonwealth Court to stop Hanes from issuing any more licenses or accepting marriage certificates from gay and lesbian couples.
The suit alleged that Hanes "risks causing serious and limitless harm to the public" by issuing the marriage licenses. The suit also says that Hanes' actions create "administrative and legal chaos" and leave couples "to believe erroneously that they have entered into a valid marriage under the law of Pennsylvania."
Ray McGarry, Montgomery County's solicitor, told reporters Friday that the Health Department has no legal standing to sue over the enforcement of Pennsylvania's laws. Aimee Tysarczyk, a Health Department spokeswoman, declined to comment because the case was ongoing.
McGarry said state law allowed for the matter to be pursued in court by the attorney general, a county district attorney, or a private citizen who claimed he or she had been harmed in some way.
State Attorney General Kathleen Kane, a Democrat, has refused to defend the ban cited in the ACLU lawsuit.
Montgomery County District Attorney Risa Vetri Ferman, a Republican, said she did not have jurisdiction over every law in the Commonwealth.
"Based upon the current law of Pennsylvania, a same-sex marriage license is not legally valid," she told The Inquirer. "However, the remedy for issuing an invalid marriage license does not include intervention by the Office of the District Attorney."
County Commissioner Bruce L. Castor Jr., a former Montgomery County district attorney, said the district attorney does have the legal standing to take action against the register of wills.
In 2004, when a question about same-sex marriage came up in Montgomery County, then-District Attorney Castor said he would take immediate legal action if such licenses were issued.
Castor said his stance was based on the state criminal code: "A person commits a misdemeanor of the second degree if he intentionally obstructs, impairs, or perverts the administration of law or other governmental function by ... breach of official duty, or any other unlawful act," which still applies today.
Castor said he had not spoken with Ferman, his former first deputy. He would not speculate on why she has refused to use the same tactic.
Engle, the Penn State law professor, said the question of who could sue the county was a minor issue before a court examines the actual law.
"The question is really whether or not people have the right to marry the person of their choice regardless of gender," Engle said.
She declined to predict how a court might rule.
"That's a scary place to go," she said. "But you can't ignore the recent Supreme Court decision when you examine this issue."
Contact Ben Finley at 610-313-8118 or firstname.lastname@example.org, or follow on Twitter @Ben_Finley. Get more Bucks County news at Inquirer.com/bucksinq.