Republicans in Pennsylvania went to court during the midterm campaign to try to get Democratic candidate Lindsey Williams kicked off the ballot over alleged residency deficiencies. A judge threw their challenge out, and Williams went on to upset her opponent, flipping a seat tucked inside Conor Lamb’s congressional district.

Now Senate Republicans, who still control the upper chamber despite losing five seats and the popular vote statewide, are trying to use the same residency argument to refuse seating the winner of the race.

Majority Leader Jake Corman, Senate President Pro Tempore Joe Scarnati, and the state GOP claim that by the time of the election, Williams was ineligible to run and therefore shouldn’t be able to take her seat in January.

Scarnati wrote Williams, 35, a letter in late November telling the incoming senator that she’d have to pay back her December salary if it was determined that she did “not meet the constitutional requirements.” The letter offered Williams, an attorney who’s worked with the Pittsburgh Federation of Teachers for four years, a hearing in front of Scarnati and a bipartisan commission.

A federal judge in October threw out the initial lawsuit brought by two voters, supported by the state GOP, claiming that Williams didn’t meet residency requirements on the grounds that the filers had missed the deadline to challenge her eligibility. He wrote in that opinion that the question was an “untimely” and “barely colorable claim.”

The race in itself was bizarre. Allegations surfaced that her opponent Jeremy Shaffer was behind campaign signs saying that Williams was a socialist, manufactured to look like her own. Shaffer says he did not create the signs, but his campaign manager is treasurer of the group that paid for them. And television ads he ran against Williams made the same claim.

If Senate Republicans declare Williams ineligible, the state would have to hold a special election to fill the seat.

“I’m not sure what’s gained by having to redo this election,” Williams’s lawyer Chuck Pascal told The Intercept. “To have a special election that will be costly to both the county and both parties, to have her run in a special where she will clearly be eligible. And deprive the people of the district of a senator for six months,” he explained. “I mean the last campaign cost almost a million dollars on each side. So, it would just seem to me to be a waste of money at this point.”

Williams is cooperating with GOP requests for documentation proving her residency, including but not limited to copies of her driver’s licenses, residential lease and purchase information, and tax documents for the past four years. They asked that Scarnati extend his original deadline for the documents to December 10.

“The constitution is not a guideline,” Corman spokesperson Jennifer Kocher said in response to criticism that a special election would be a waste of money. “If she can provide us with that information that will clear any of those questions up, then we’ll just move on,” she told The Intercept.

If Senate Republicans have more questions after they review those materials and decide to call a hearing, Pascal said he and his client would participate. “We don’t think it’s necessary,” he said.