Thursday’s Supreme Court ruling that President Obama’s “recess” appointments to the National Labor Relations Board were unconstitutional could mean as many as 800 cases decided by the illegal appointees would have to be reconsidered.

The Court ruled three appointments President Obama made on Jan. 4, 2012, to fill out the five-member National Labor Relations Board, were improper because the Senate was not, in fact, in recess. That means the NLRB did not have a quorum, as required by law, when it ruled on hundreds of cases from the time they were appointed until August 2013, when other nominees were properly confirmed by the Senate and sworn in as members. This, in turn, calls into question all the decisions the NLRB rendered during that time.

Richard Cordray, the head of the Consumer Financial Protection Bureau, was appointed the same day and under the same circumstances as the NLRB appointees. But Cordray later was later confirmed by the Senate, and he subsequently ratified the agency’s actions taken while he served as a recess appointee.

But the NLRB did not ratify its past actions, even after the Senate approved four new members, giving the board a quorum as of August 2013. Now, it may have to reconsider every case that was appealed to the federal appellate courts on the basis of the lack of a quorum, as well as an unknown number of other cases decided by the board in which the unconstitutional recess appointees participated.

Moreover, parties that lost their cases during this time but had yet to appeal to a federal appellate court still may be able to appeal because the National Labor Relations Act does not include a statute of limitations for appeals—as several appellate courts have noted, most recently in Buchanan v. NLRB. Some appeals may be barred by the equitable doctrine of laches, which discourages litigants from “sleeping on their rights.”

A similar situation arose following New Process Steel v. NLRB, in which the Supreme Court held that the board could not exercise its statutory authority without a quorum of three members. Following that decision, the board individually reviewed nearly 200 cases that had been adjudicated while it lacked a quorum. The Noel Canning decision could affect 400-800 cases.

Noel Canning, a bottling company that distributes Pepsi products in Yakima, Wash., was charged with unfair labor practices in connection with contract negotiations with its Teamsters local in 2010. An administrative law judge ruled against the company, and on appeal, a three-member panel of the board—including two of the recess appointees—agreed. Noel Canning then challenged the board’s decision in federal court on the basis the board lacked a quorum to act, leading to the D.C. Circuit’s ruling that the recess appointments were unconstitutional. It was this ruling the Supreme Court unanimously affirmed on Thursday.