As the Court holds, the pro forma sessions like the one Obama used to appoint the NLRB members are full sessions, as long as that's what the Senate says. Or, as the Court puts it, "the Senate is in session when it says that it is."
"We conclude that we cannot ignore these pro forma sessions," Breyer wrote.
As Tom Goldstein writes at SCOTUSblog, the decision significantly limits presidential power. While the president can still make recess appointments without Senate confirmation when the Senate says it's in recess, the House or Senate "can take the Senate out of recess and force it to hold a 'pro forma session' that will block any recess appointment." Which means, the party in power of the House or Senate will be able to block recess appointments easily.
There is a lot in the balance here, from what the decision means for NLRB decisions since the appointments were made to what it means for the NLRB itself. And in his opinion, Breyer made it clear that he knows the stakes.
"We have not previously interpreted the Clause," Breyer writes, referring to the Recess Appointments Clause in Article II of the Constitution, "and when doing so for the first time in more than 200 years, we must hesitate to upset the compromises and working arrangements that the elected branches of Government themselves have reached."
In case you're wondering, here's that clause in full:
The President shall have Power to fill up all Vacancies that may happen during the Recess of the Senate, by granting Commissions which shall expire at the End of their next Session.
In the view of the Court, as written by Breyer, "pro forma sessions count as sessions, not as periods of recess. We hold that, for purposes of the Recess Appointments Clause, the Senate is in session when it says it is, provided that, under its own rules, it retains the capacity to transact Senate business. The Senate met that standard here."
In his concurrence (which was joined by Roberts, Thomas, and Alito), Scalia makes the case that the Court's opinion was too narrow. Rather than allow presidents to make appointments during breaks 10 days or longer, Scalia, and the Court conservatives who joined his opinion, hold that a "recess" is just the period between two sessions of Congress.
I would hold that "the Recess" is the gap between sessions and that the appointments at issue here are invalid because they undisputedly were made during the Senate's session. The Court's contrary conclusion — that "the Recess" includes "breaks in the midst of a session," ante, at 9 — is inconsistent with the Constitution's text and structure, and it requires judicial fabrication of vague, unadministrable limits on the recess-appointment power (thus defined) that overstep the judicial role.
Scalia and his conservative colleagues hold that a "recess" is just the period between two sessions of Congress, not something that's just a 10-day break or longer. They take issue with a "colloquial" definition of "recess" that's used in cases that, as they see it, are really just adjournments during a session. Using "recess" during these times "leaves the recess-appointment power without a textually grounded principle limiting the time of its exercise," Scalia writes.