This week, a federal appellate court struck down the National Labor Relations Board’s (NLRB) “poster rule,” finding that the agency does not have the authority to issue such a rule.

The poster rule requires more than 6 million employers to post notices at work informing employees of their rights under the National Labor Relations Act, undercutting employers’ free speech rights to engage in noncoercive speech about unionization. The NLRB threatened to make the failure to comply with the poster rule an unfair labor practice and evidence of an employer’s “antiunion animus” for claims before the NLRB.

In early May, the D.C. Circuit struck down the poster rule, finding that it violated the free speech rights of employers. This week, the Fourth Circuit agreed that the poster rule is invalid, finding that the NLRB exceeded its authority in issuing the rule. This is a much broader ruling, and the Fourth Circuit held that the NLRB’s role is limited to conducting representative elections and addressing unfair labor practice charges.

Unlike many other federal agencies, the court stated, the NLRB lacks the authority to promulgate notice requirements because Congress never intended to delegate to the NLRB “proactive rulemaking.” While the NLRB could require employers who had been adjudicated to have committed unfair labor violations to post such notices, “[n]o provision in the [National Labor Relations Act] requires employers who have not committed labor violations to be subject to a duty to post employee notices.”

Yesterday’s ruling by the Fourth Circuit highlights one reason why President Obama recently turned his attention to packing the D.C. Circuit with judges of his choosing (despite its low caseload compared to other overworked courts): It hears many suits involving federal agencies, and it has repeatedly smacked down the Obama Administration.

From EPA regulations to non-recess appointments and the NLRB poster rule, the Obama Administration has not fared well before the D.C. Circuit, which has laid the foundation for other courts to follow suit. But the confirmation of three nominees to that court could change the balance.