In NLRB v. Noel Canning, whatever the differences between the bare majority of five justices led by Justice Breyer and the four dissenters for whom Justice Scalia wrote, there is no question between the contending sides that President Obama acted unconstitutionally in making three ostensible recess appointments to the National Labor Relations Board.

To see what the president did: Consider that the Senate had adjourned on December 17, 2011, under a unanimous consent agreement providing that it would “convene for pro forma sessions only, with no business conducted,” every three days (not counting holidays) from December 20, 2011, through January 20, 2012, adjourning at the end of each pro forma session. The Senate followed that schedule, duly convening the pro forma sessions, which, as defined by the Congressional Research Service, are “short meetings of the Senate or House held for the purpose of avoiding a recess of more than three days and therefore the necessity (under the Adjournments Clause) of obtaining the consent of the other House.” The intention with such sessions is not to do business, though business may be and sometimes is done (and was in this instance). Since the mid-19^th century pro forma sessions have been used on many occasions and for various purposes, including, in the case of the Senate, to preserve its advice-and-consent authority.