A silent spring descended on House and Senate chambers March 25 when Congress left town for its two-week break. During five recesses last year, banging gavels reverberated in both nearly empty chambers as designated presiding officers convened and adjourned pro forma sessions in a matter of seconds. The hapless victims: House and Senate floor staff.

Senate Majority Leader Harry Reid, D-Nev., perfected the pro forma session device in 2007-2008 to block President George W. Bush from making a recess appointment to the federal bench. Traditionally, presidents did not make recess appointments during recesses of fewer than 10 days. Under the Constitution neither house can adjourn for more than three days without consent of the other. While Reid granted the House longer recesses, he convened his chamber every fourth day during the last 14 months of the Bush administration. The result: 60 pro forma days spanning 11 recesses.

When Republicans retook the House in 2011, Speaker John A. Boehner of Ohio, in consultation with Senate Minority Leader Mitch McConnell of Kentucky, turned the tables by forcing the Senate (and, by default, the House) to hold pro forma sessions during two recesses to block President Barack Obama from making any recess appointments. But Obama had other ideas. On Jan. 4, 2012, between two pro forma days, the president made four recess appointments — three to the National Labor Relations Board and one to head the Consumer Financial Protection Bureau.

The president did not provide a simultaneous written legal defense of his unprecedented surprise attack. However, the defense came two days after the offense when the White House released a legal memorandum prepared by the Justice Department’s Office of Legal Counsel. The OLC argument: Pro forma sessions aren’t real sessions because no legislation is scheduled and the Senate does not have a quorum to receive nominations, let alone act on them. The actual recess period, the OLC asserts, was from Jan. 3, 2012, the first day of the second session, to Jan. 23, the first day legislative activity was scheduled to resume, notwithstanding four interim pro forma days.

The legal memo indicated its analysis relied heavily on a Department of Justice staff “memorandum to file” dated Jan. 9, 2009, during the waning days of the Bush administration. That earlier memo, however, never received official sanction by the Bush White House nor Justice Department, let alone a test flight over (or around) the Senate.

Nevertheless, the Obama White House thrust it forward as a bipartisan shield against what its memo concedes poses “some litigation risk for such appointments.” That risk became manifest this year on Jan. 25, when a three-judge panel of the U.S. Court of Appeals for the D.C. Circuit ruled that hundreds of decisions taken by the NLRB were unlawful because three of its members were unlawfully appointed.

The D.C. appeals court held that the president can make recess appointments only during intersession recesses, that is, recesses that occur between the first and second sessions, and then only for vacancies that arise during those recesses. That is based on the court’s literal reading of the Constitution: “The President shall have the power to fill up all vacancies that may happen during the recess of the Senate” — not “a recess.” Obama’s appointments were made to pre-existing vacancies one day after the second session convened.

The fact that Congress has taken January and spring recesses this year without the accompanying pro forma charades indicates the White House is giving the Senate informal assurances it will not attempt any recess appointments. Such assurances were proffered sporadically in past years, but will presumably be more regular this year to avoid jeopardizing any further agency or court decisions pending high-court action on the NLRB case.

Ideally, this armistice period could have opened the way for the two branches to establish a more reliable appointments protocol. However, four stalled nominations to the D.C. Court of Appeals have soured that possibility: Reid is threatening to reactivate “the nuclear option” of changing filibuster rules by majority vote if Republicans don’t yield. Enjoy your recesses while you can: This silent spring could turn to nuclear winter.