Which Party Controls the Pennsylvania House? It’s TBD.

“We won 102 districts compared to the Republicans’ 101,” Joanna McClinton, the House Democratic leader — and, according to her, the majority leader — said in an interview. “It’s a fact, it’s indisputable.”

Within hours of her two fellow Democrats’ resignations last week, Ms. McClinton was sworn into office in an otherwise empty House chamber. She then scheduled elections for all three of the vacant seats on Feb. 7, the earliest date possible under state rules, and Pennsylvania’s acting secretary of state, a Democrat, signed off on the plan.

Republicans were livid, accusing the Democrats of having staged a “paperwork insurrection.” Within days, Representative Brian Cutler, the leader of the House Republicans, sued the secretary of state, arguing that Ms. McClinton was not the House majority leader and thus lacked the authority to set special elections.

On Monday morning, it was Mr. Cutler’s turn to be sworn in on the House floor. In an interview afterward, he said that since he was the House Republican leader and since there were 101 Republicans ready to take office, compared with 99 Democrats, “the math makes me the majority leader.”

Mr. Cutler said that he would soon submit his own dates for the special elections but that the recent moves by the Democrats had made it too complicated to figure out the dates just yet.

What happens now is anyone’s guess.

Adam Bonin, an elections lawyer in Philadelphia who has long worked with Democrats, said the stakes were significant. “This isn’t just about who’s in charge of this chamber for the first month,” he said. “This really is about all sorts of potential exercises of power.”

Among them is a Senate bill that would put a handful of constitutional amendments proposed by Republicans on a statewide ballot — including ones that would establish a voter ID requirement, expand the legislature’s power and assert that there is no state constitutional right to abortion. If each chamber approved the bill during the upcoming legislative session, the questions would be put to a statewide vote.