The D.C. Circuit issued a significant decision last week that boldly challenges President Obama’s executive power.

On Friday, a unanimous three-judge panel for the D.C. Circuit ruled that the president violated the Constitution when he bypassed the Senate and appointed Sharon Block, Richard Griffin and Terence Flynn to fill vacancies on the National Labor Relations Board (NLRB) last year.

Republican senators had spent months blocking Obama’s choices because they claimed the resulting board would be too union-friendly. The president contends that he acted properly because the Senate was away for the holidays on a 20-day recess, but the court said the Senate was technically still in session.

The D.C. Circuit’s decision is the first time a federal appeals court has ruled that the Constitution limits the president’s power to make recess appointments in between Congressional sessions. Presidents have made recess appointments during Senate breaks since 1867.

The Obama administration likely will appeal the decision to the Supreme Court. If the ruling stands, the NLRB would only comprise one validly appointed member, thus effectively shutting it down; three sitting board members must be present to issue decisions. Additionally, hundreds of NLRB decisions in the past year would be invalid.

“If this opinion stands, I think it will fundamentally alter the balance between the Senate and the president by limiting the president’s ability to keep offices filled,” John P. Elwood, who handled recess appointment issues for the Justice Department during the George W. Bush administration, told the New York Times. “This is certainly a red-letter day in presidential appointment power.”

The D.C. Circuit’s decision also could affect a separate legal challenge to another one of Obama’s recess appointments—Richard Cordray, whom the president named head of the Consumer Financial Protection Bureau.

Read Bloomberg and NPR for more information.

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