Geoff Burr, Associated Builders and Contractors vice president of federal affairs, notes that the Senate approved the extension of the payroll tax cut by voice vote during the 2012 pro forma session, an indication that it was conducting legislative business. “I’m very confident that we’re going to win on the pro forma issue,” says Burr, who also is chair of the Coalition for a Democratic Workforce.

Denise Keyser, a partner with the labor and employment group at Philadelphia-based law firm Ballard Spahr LLP, says that if the court upholds part or all of the D.C. Circuit opinion, all NLRB rulings since January 2012—at the very least—would be invalid and have to be reheard when the board has a full, five-member complement.

Early this year, Obama nominated a full slate of individuals to the board, including Democrats Block, Griffin and Chairman Mark Gaston Pearce, as well as two Republicans. The Senate’s labor committee approved all five nominations in May. There has been no floor action on those nominations yet.

Committee Chairman Tom Harkin (D-Iowa) called the appeals court’s decision “a radical departure from precedent.” He added that “Democratic and Republican presidents alike have made liberal use of intrasession recess appointments for years.” Harkin pledged to fight to get a full slate of nominees confirmed.

Josh Goldstein, an AFL-CIO spokesman, said, "We hope the Supreme Court will reverse the D.C. Circuit's radical ruling. But workers can't wait for the Supreme Court—we need the Senate to confirm the bipartisan package of NLRB nominees now."

But attorney Keyser believes that the full Senate won’t act on the nominations until after the high court has ruled. “This is a fight between the two branches” of the government, she says.

Story updated on June 25