In a long-awaited monumental opinion, the Supreme Court today held unanimously that President Obama’s purported “recess appointments” to the National Labor Relations Board in January 2012 were unconstitutional. The Court rejected the President’s arguments that he could unilaterally determine that the Senate was in recess, even when the Senate was holding one-minute “pro forma sessions” for the express purpose of avoiding a recess. The decision immediately calls into question the validity of hundreds of decisions issued by the unconstitutionally appointed Board members and raises serious doubt as to the future of the recess appointment.

Though the Court unanimously concluded that the appointments were unconstitutional, the nine justices were divided in how they reached that conclusion. Justice Breyer, writing for a five-justice majority, rejected the sweeping conclusions of the D.C. Circuit that we covered back in 2013. Instead, the majority concluded (1) that the President has the authority to fill vacancies that arise prior to the recess, and (2) that the recess appointment clause applies to both “intrasession” and “intersession” recesses. However, the majority concluded more narrowly that the Senate has the power to decide when it is in session and when it is in recess. Because the Senate claimed that it was not in recess when President Obama made the appointments in January 2012, there was no recess and no right to fill the vacancies using the recess appointment power.

In a lengthy concurrence, Justice Scalia agreed with the basis for the D.C. Circuit’s prior ruling and would have held that the Recess Appointments Clause applies only to the recess between two sessions of the Senate, and not to breaks during the session. He also would have held that the recess appointment power is limited to vacancies that first arise during the recess, not to vacancies existing before the recess started.

The opinion is groundbreaking for two reasons. First, it casts immediate doubt on the ongoing validity of hundreds of decisions issued by the Board from 2012 until it finally obtained a Senate-approved quorum in August 2013. While the Supreme Court did not specifically pass upon the effect of its decision on other cases issued during the tenure of the recess appointees, it indicated earlier that decisions issued by the Board without legal authority to issue them may be invalid. In 2010, the Supreme Court issued an opinion in New Process Steel v. NLRB holding that the Board needed three members to have a quorum. Because the Board never had three members approved by the Senate between January 2011 and August 2012, the Supreme Court said the decisions the Board issued during that period may not be enforceable, especially if they are still subject to legal challenge. After the New Process Steel decision, it took the Board several months to reissue new decisions and eliminate its backlog. The same may be in store here.

Second, even though the majority’s reasoning was more narrow than Justice Scalia’s concurrence or the D.C. Circuit opinion, the decision is still likely to curb future use of recess appointments. The Supreme Court held that any recess of less than 10 days is presumptively too short to support a recess appointment. Accordingly, to avoid giving rise to the President’s recess appointment power, the Senate would need to do no more than hold a one-minute session once a week (similar to the “pro forma sessions” they were holding in January 2012). Additionally, the House of Representatives can prevent the Senate from adjourning for more than three days at a time by refusing to consent to a longer adjournment. So the House can also prevent the Senate from going into recess and allowing the President to make recess appointments. Going forward, as long as one house of Congress is controlled by a different party than the President, that house has an effective veto against future recess appointments.

We can expect more to develop in the wake of this significant decision in the coming weeks and months, particularly with respect to what will happen to the ongoing validity of the Board’s decisions between 2012 and August 2013. Stay tuned.

The case is NLRB v. Noel Canning, No. 12-1281.