Tom Goldstein at SCOTUSBlog summarizes:
Here is the upshot of the decision. The President can make a recess appointment without Senate confirmation when the Senate says it is in recess. But either the House or the Senate can take the Senate out of recess and force it to hold a “pro forma session” that will block any recess appointment. So while the President’s recess appointment power is broad in theory, if either house of Congress is in the hands of the other party, it can be blocked.
Big Media is portraying this as a setback to Obama:
The US Supreme Court today limited a president’s power to make recess appointments when the White House and the Senate are controlled by opposite parties, scaling back a presidential authority as old as the republic.
The case arose from a political dispute between President Obama and Senate Republicans, who claimed he had no authority to put three people on the National Labor Relations Board in January 2012 when the Senate was out of town.
He used a president’s power, granted by the Constitution, to “fill up all vacancies that may happen during the recess of the Senate.” But the Republicans said the Senate was not in recess at the time the appointments were made, because every three days a senator went into the chamber, gaveled it to order, and then immediately called a recess.
By a unanimous vote, the Supreme Court agreed that the Senate was not in recess, holding that it’s up to both houses of Congress to define when they’re in session or in recess. As a result of the decision, the Senate can frustrate a president’s ability to make recess appointments simply by holding periodic pro forma sessions, a tactic used in recent years by both political parties.
But the folks at SCOTUSBlog say Scalia is reading a long concurrence, saying that while he agrees with the unanimous Court that the appointments are invalid, there is no basis for recess appointments in the Constitution, period.