Virginia Supreme Court Justice Jane Marum Roush. (Bill O'Leary/Washington Post)

The GOP’s plan to replace the Virginia Supreme Court justice whom Gov. Terry McAuliffe (D) put on the bench could be undone by a moderate Republican state senator, who hinted Friday that he might not agree to install someone else.

Republicans need all 21 of their senators or a Democratic defector to pull off a scheme that would be unprecedented in modern times: unseating a sitting state Supreme Court justice by electing someone else to the slot.

Sen. John C. Watkins (R-Powhatan), who has said he is retiring in January partly out of frustration over increasing partisanship in Richmond, hinted that he might not go along with the plan to replace Justice Jane Marum Roush when the legislature convenes Monday for a special session on redistricting.

“It is very frustrating to me that we would potentially expend the appointment of an excellent Supreme Court justice for what seems to be political reasons,” Watkins said in an interview with The Washington Post. “It’s all about politics and this redistricting thing. Both sides have made some mistakes, and it brought us to this point. I personally think it’s time for both sides to back off and start talking to each other and not past each other.”

Watkins declined to say how he plans to vote. Another departing moderate Republican, Sen. Walter A. Stosch (Henrico), said he was undecided. The refusal of one or both of them to go along with the plan would, absent any Democratic defections, stop the GOP from delivering what appeared to be an imminent and embarrassing blow to the governor.

McAuliffe is likely to make the case in fall legislative elections and in the 2016 presidential contest that the Republican Party has veered too far to the right, even for some of its own members.

Resistance from Watkins and Stosch would not necessarily keep Roush on the bench. Unless the General Assembly elects her, Roush’s term expires 30 days after lawmakers convene even if they don’t choose someone else to replace her.

Also on Friday, Roush broke her silence on the controversy, saying she was hopeful that she would be allowed to stay on the bench. While legislators on Monday interview state Court of Appeals Judge Rossie D. Alston Jr. — their proposed replacement for her — Roush said she will be at work in her office in the Supreme Court in Richmond.

“I remain optimistic that I will be elected to a 12-year term on the Supreme Court on Monday, that this process will turn out in my favor ultimately,” she said, adding, “Maybe not Monday. . . . I’m not a quitter. I’m going to see this through to the end.”

Roush, a former Fairfax County Circuit Court judge, said the past two weeks have been a mix of emotions, as Republican leaders threatened to unseat her and prominent members of the legal community — including 24 past bar association presidents — have stepped up to defend her.

“I was surprised by the turn of events, that my election was jeopardized,” she said. “However, I have been extremely heartened and humbled by the outpouring of support from all over the commonwealth in favor of retaining my seat. To a certain extent, I feel like I’ve been at my own funeral, since they’re saying such nice things about me. The resolutions from the various bars, the letters from the bar presidents, the online petition — it’s really been amazing. The one thing that everyone has said to me is, ‘It’s terrible this is happening, but nobody has said anything negative about you.’ I think I’ve stayed in remarkably good spirits, frankly.”

Roush confirmed that legislators had offered to put her back on the bench in Fairfax, but she declined.

“My chambers [in Fairfax] are gone, occupied by another judge, my docket has been reassigned. It’s too difficult to reconstruct that, so I did decline that,” she said.

Legislators also said they would consider her for Alston’s seat on the Court of Appeals, but she was not interested in that, either.

The docket of the Court of Appeals is limited to three subject areas: domestic relations, criminal and workers’ compensation, she said. “And I had no experience as a lawyer in any of those three areas. So I don’t think the docket of that court plays to my strengths as a judge. I think I can make a greater contribution on the Supreme Court, whose docket contains the types of cases that I was experienced with as a practicing attorney and I gravitated toward as a judge.”

McAuliffe has ordered legislators back to Richmond starting Monday to draw a new congressional map, which a federal court ordered them to do by Sept. 1. The Republican-led House and Senate plan to use the session to unseat Roush, whom McAuliffe appointed to the Supreme Court on an interim basis in July.

The General Assembly normally makes judicial appointments. The governor may fill vacancies when the legislature is not in session, which McAuliffe did when he installed Roush on July 27. Such appointments, however, require confirmation by the legislature 30 days after it next gavels into session.

GOP legislators have said they have no complaints about Roush, who has presided over high-profile cases, including the trial of D.C.-area sniper Lee Boyd Malvo. But they note that judicial appointments are theirs to make and that they prefer Alston, who has served on the Court of Appeals since 2009 and was previously a judge on the Prince William Juvenile and Domestic Relations District Court and chief judge of the Prince William Circuit Court. They also complained that McAuliffe did not confer with House or Senate leaders before making his nomination.

McAuliffe’s choice has the support of the legislative black caucus despite the fact that Alston is an African American. The governor has accused Republicans of throwing a “political temper tantrum.”

Stosch said he was not sure whether he will support the GOP plan to unseat Roush, saying he was still trying to understand the political dynamics that brought the legislature and governor to this point.

“I don’t know how we got to where we are, and I’d like to hear that discussion,” he said.

The possibility that the Senate leadership will not hold on to all of the Republicans has led both sides to start plotting procedural moves and counter moves.

Republicans are confident that they can block McAuliffe from giving Roush another recess appointment. The most obvious way: refusing to formally adjourn — a tactic the GOP used in a 2014 special session that was not gaveled to a close until opening day in January.

Some Republicans said another way would be to call a vote on Roush herself if Alston falls short. The state constitution prohibits governors from reappointing a candidate to a job requiring legislative confirmation if either chamber has rejected the nominee. Del. Terry G. Kilgore (R-Scott) said that option would apply here.

But Mary Kate Felch, a senior research associate on the Senate Courts of Justice Committee, said that constitutional provision does not apply to judges because legislators directly elect them instead of confirming the governor’s picks.