President Bill Clinton filled 139 posts that way in his eight years in office, the research service said.

But Obama was the first president to try to make recess appointments when Congress explicitly said it was not in recess. The Constitution requires that the Senate and House must get the other's consent for a break lasting longer than three days. At the end of 2011, the Republican-controlled House would not give the Democratic-led Senate permission for a longer break.

The partisan roles were reversed during Bush's presidency, when Senate Democrats sought ways to prevent the president from making recess appointments.

In fact, the very basis on which the justices decided the case — that the Senate can use extremely brief sessions to avoid a formal recess — was a tactic devisedsaid.

A recess appointment can last no more than two years. Recess appointees who subsequently won Senate confirmation include Chief Justice Earl Warren and Justice William Brennan, Federal Reserve Chairman Alan Greenspan, two current NLRB members and Consumer Financial Protection Bureau director Richard Cordray. Former UN Ambassador John Bolton is among recess appointees who left office because they could not win a Senate vote.

The case challenging the appointments was brought by Noel Canning, a soft drink bottling company in Yakima, Washington. The company claimed an NLRB decision against it was not valid because the board members were not properly appointed and that the board did not have enough members to do business without the improperly appointed officials.

Noel Canning prevailed in the U.S. Circuit Court of Appeals for the District