HARRISBURG – A federal judge on Friday ordered a month-long delay in a case that seeks to bar the use of a specific voting machine in the upcoming presidential primary.

Hearings were to begin Tuesday in U.S. District Court in Philadelphia to determine whether the ExpressVote XL touchscreen tabulator violates a legal settlement that set higher standards for election security in Pennsylvania.

Philadelphia, Northampton and Cumberland counties selected the XL as part of an election system update required of all Pennsylvania counties by the end of 2019. The delay ordered by the judge leaves the counties in limbo. Officials from the counties and the Pennsylvania Department of State say shelving the XL and shifting to different voting systems so close to the election would create chaos for voters. They say plaintiffs could and should have acted sooner — and U.S. District Judge Paul Diamond agreed with that point in the order issued Friday.

A key issue in Diamond’s decision to delay the next hearing until Feb. 18 is the potential that one of the plaintiffs attorneys, Ilann Maazel, could be called as a witness by the DoS. If the state insists on calling Maazel, Diamond said he would remove the lawyer from the case. The delay, the judge said, is intended to give the plaintiffs time to prepare new counsel.

The delay also is a nod to University of Michigan computer science professor and election security expert Alex Halderman, a key witness who is out of the country until next week on a trip planned before Diamond initially scheduled the case.

Maazel negotiated the settlement on behalf of the plaintiffs and, as part of that, he and Halderman discussed voting systems and other issues with DoS.

Settlement discussions are generally confidential. Exceptions, however, include “negotiations related to a claim by a public office in the exercise of its regulatory, investigative, or enforcement authority,” notes Dickinson School of Law professor Anne Toomey McKenna.

“But, the situation for disqualification could’ve been avoided if there was more specificity in settlement itself,” McKenna says. “The parties didn’t write out a settlement agreement that was clear … and the lack of clarity has created the potential need for an attorney to testify.”

While ethical rules disqualify attorneys from handling cases where they’re also a key witness, there are multiple exceptions — including scenarios where removing the lawyer would cause an undue hardship for their clients. Diamond appeared to address that issue by giving the plaintiffs time to find alternates to argue the case, if necessary, according to attorney Chester Corse, past president of the Pennsylvania Bar Institute.

Maazel argued he’s not the only one who can testify to the settlement talks. And the others wouldn’t be limited by attorney-client privilege, as he might be, he and his colleague Doug Lieb said in a Jan. 15 court filing.

Lieb also tried to persuade the judge to let him handle the case if Maazel can’t.

But Diamond wasn’t having it.

“You (could) be in the position of cross-examining your own partner as to whether or not he’s telling the truth, or he’s getting it wrong,” Diamond said during a conference call last week. “Or you won’t cross examine your own partner, because he’s your partner. And the plaintiffs get shortchanged.”

The plaintiffs are still “weighing their options” for backup attorneys, according to Dave Schwab, spokesman for Jill Stein. The former Green Party presidential candidate is the lead plaintiff on the case, which began as a recount attempt after the 2016 election.

The settlement, in part, drove the mandate for all 67 Pennsylvania counties to switch to paper-based voting systems by the end of last year.

Stein and her team now claim the XL doesn’t adhere to the terms of the deal because it doesn’t employ a paper ballot as defined by state law. Its use of barcodes also prevents voters from verifying their choices before casting their ballots, they allege.

Meanwhile, proceedings start Thursday in another lawsuit over the XL filed in Commonwealth Court in Harrisburg a month ago.

Ahead of that, some other things to know about the two lawsuits:

1. Thursday’s proceeding will focus on whether Philadelphia, Cumberland and Northampton counties should join the case being heard in Commonwealth Court. The court called the hearing to address this question, specifically, citing the fact that counties are responsible for selecting and deploying voting machines. Philly voluntarily joined the federal lawsuit and Cumberland officials submitted affidavits detailing why they won’t have time to adjust if the XL is decertified. Neither has filed anything in the Commonwealth Court case, according to the case docket.

2. If required to conduct the primary election without the XL, the counties could use paper backup ballots already required under state law, plaintiffs in both cases say. Doing so, however, could overwhelm tabulation efforts already expected to be overwhelmed with the advent of excuse-free mail-in ballots this spring. That prospect already has some jurisdictions looking to buy more scanners, since most counties had already finalized their voting machine contracts (or were close) when state lawmakers advanced an election code overhaullast fall. The changes include new rules for mailing ballots, calculating paper backup ballot quotas and voter registration deadlines.

3. The Department of State recently tested an update for the XL that would resolve some concerns about the device. The software update from ES&S would, among other changes, give counties the option of using the XL as a ballot-marking device. That means the machine would print a ballot reflecting a voter’s choices; the voter would be able to review that ballot in-hand before it would be fed into a scanner by the voter or later by election workers. Currently, the XL displays a printout of a voter’s selections in a window that renders the text unreadable for some voters. ES&S also has equipped the XL’s control panel with an alarm triggered whenever it’s opened. Critics have said the panel’s lock could be “easily picked” without detection since it’s accessible to voters while they’re behind a curtain making their ballot selections. DoS officials and their contractors spent more than 20 hours Jan. 6-8 running mock elections that entailed filling out, scanning and tabulating hundreds of ballots on the XL and other ES&S devices certified in Pennsylvania. DoS won’t make a certification decision for a couple months yet, but the federal Election Assistance Commission already approved the update last fall.

4. DoS already defended its certification of the XL. The National Defense Coalition and Protect Our Vote Philly, two groups named on the Commonwealth Court case, led an effort last summer to get the state to voluntarily decertify the XL. That failed; instead, DoS doubled down on its approval after state officials conducted a re-examination offsite and without public notice, sparking criticism among fair election advocates.

5. Diamond doesn’t want to get into the XL’s disastrous debut in Northampton County — or testimony from Philly voters about their problems using the machine — at the Feb. 18 hearing in the federal lawsuit. “None of them are plaintiffs in this case,” Diamond said on last week’s conference call. “I just don’t see what they have to contribute to what the settlement agreement means and what the parties meant. … To have these voters testify, to have them say these are lousy machines (and I assume that’s what they’re going to say) — that’s not my job, to determine whether they’re good machines.”