Senate Republicans have retained one-time Republican judicial nominee Miguel Estrada to file an amicus brief in a lawsuit challenging the recess appointment of three members to the National Labor Relations Board in January.

“The president’s decision to circumvent the American people by installing his appointees at a powerful federal agency, when the Senate was not in recess, and without obtaining the advice and consent of the Senate, is an unprecedented power grab,” Senate Minority Leader Mitch McConnell (R-Ky.) said in a release. “We will demonstrate to the court how the president’s unconstitutional actions fundamentally endanger the Congress’s role in providing a check on the excesses of the executive branch.”

Asked for his thoughts on the move, Majority Leader Harry Reid said it made no difference to him.

“I don’t care,” the Nevada Democrat said.

Noel Corp., a Washington-based business that bottles and distributes soft drinks, brought the suit, which is before the U.S. Court of Appeals for the D.C. Circuit. The company is challenging the NLRB’s determination that it must enter into a collective bargaining agreement with a labor union. The company was involved in a dispute with a local Teamsters union, and the NLRB subsequently ruled Noel violated the National Labor Relations Act.

In order to give the agency a quorum, President Barack Obama filled three spots on the NLRB, including one Republican position, with recess appointments he made in January. Obama also appointed Richard Cordray to head the Consumer Financial Protection Bureau during the recess. Republicans had threatened to filibuster his nomination because they had a number of concerns about the agency.

The move provoked Senate Republicans who questioned the legitimacy of the appointments and charged the White House with overreach. They contend Congress was not in recess when the appointments were made because they held short pro forma sessions every three days during the holiday break. The White House argues that the pro forma sessions were a gimmick and didn’t count as a bona fide session.

Republicans retaining Estrada on the issue is meant to be symbolic because Estrada was nominated by President George W. Bush in 2001 to join the U.S. Court of Appeals for the D.C. Circuit. But he was never confirmed because a Democratic filibuster prevented him from getting a vote on the floor. Democrats argued that his views were beyond the mainstream.

“Miguel Estrada is one of the country’s foremost appellate advocates,” McConnell added in his statement. “He has argued 20 cases before the United States Supreme Court, and we are gratified that he will defend the Senate’s constitutional role in the confirmation process.”

The Estrada filibuster poisoned the atmosphere in the Senate regarding judicial nominees. Then-Senate Majority Leader Bill Frist (R-Tenn.) at one time threatened to use his majority to change Senate rules to prevent future judicial filibusters.

A group of 14 Senators, seven Democrats and seven Republicans, ultimately agreed to oppose the change and fostered a detente on the filibuster of judicial nominations.

Estrada is a partner in the Washington, D.C., office of Gibson, Dunn & Crutcher and serves as co-chairman of the firm’s Appellate and Constitutional Law Practice Group. Estrada served as assistant to the U.S. solicitor general from 1992 to 1997 and previously served as assistant U.S. attorney and deputy chief of the Appellate Section of the U.S. Attorney’s Office for the Southern District of New York.