The United States Court of Appeals for the Fifth Circuit has agreed to stay the mandate on its June 11, 2026, opinion that the Horseracing and Safety Integrity Act (HISA) is partially unconstitutional after attorneys from the HISA Authority told the New Orleans-based court that an appeal to the U.S. Supreme Court is forthcoming.A mandate is the formal order that returns jurisdiction to the lower court and makes an appellate ruling effective.The case dates to a 2021 lawsuit spearheaded by the National Horsemen's Benevolent and Protective Association (HBPA) and 12 of its affiliates against the HISA Authority and the Federal Trade Commission (FTC).Last month the Fifth Circuit issued a new opinion that essentially came to the same conclusion that the same three-judge panel had reached two years ago: Even though HISA's rulemaking structure is constitutional, its enforcement provisions are not.The HBPA plaintiffs did not oppose the request for a stay, according to the HISA Authority's July 13, 2026, motion.This latest stay comes a little more than a year after the Supreme Court tasked federal appeals courts in the Fifth, Sixth and Eighth Circuits with re-examining previous opinions on cases involving the constitutionality of HISA.The Fifth Circuit case is one of three HISA-related federal lawsuits that have been simmering in the federal court system for at least five years.The Fifth, Sixth and Eighth Circuit appeals courts have all agreed that HISA's rulemaking structure is constitutional. Only the Fifth Circuit has consistently disagreed, in part, by opining that HISA's enforcement provisions are unconstitutional.The losing parties in those three cases had asked the Supreme Court to rule on the “circuit split” that resulted in differing federal appeals court opinions. But on June 30, 2025, the Supreme Court remanded those cases back to the appeals courts, asking them to take a second look based on a Supreme Court precedent that had not existed when each of those lawsuits first originated.The Sixth Circuit was the first to act on the Supreme Court's remand in an anti-HISA case led by the states of Oklahoma, West Virginia and Louisiana. On Dec. 17, 2025, the Sixth Circuit upheld the constitutionality of HISA for a second time.The states on the losing side of that opinion, on May 15, 2026, petitioned for a “writ of certiorari,” which is the formal term for asking the Supreme Court to take up a case.In the Eighth Circuit anti-HISA case, the plaintiffs are executives with the Arkansas and Iowa HBPA chapters. On September 20, 2024, the Eighth Circuit affirmed a ruling out of a lower federal court in Arkansas denying a preliminary injunction the horsemen had sought to halt HISA and its Anti-Doping and Medication Control program. The Eighth Circuit has not yet issued any revised ruling to comply with last year's Supreme Court remand.The Supreme Court will likely to wait until all three related cases have been decided on remand before choosing whether or not to take them on yet again.U.S. Supreme Court | GettyA stay of the mandate has three immediate legal effects: 1) The appellate judgment is temporarily not effective; 2) The lower district court cannot act to implement the Fifth Circuit's judgment; 3) The legal status quo is preserved while the stay request is resolved, preserving the Supreme Court's ability to review the case meaningfully.If the mandate were to issue and the lower court acted on it, it could be difficult–or impossible–to undo those actions if the Supreme Court later agreed to hear the case.The July 13, 2026, motion from the HISA Authority's legal team described its rationale for the request:“The Court should stay its mandate by July 24 (before expiration of the time for seeking rehearing) pending the filing and disposition of the Authority's forthcoming certiorari petition. All parties to this litigation have confirmed that they do not oppose entry of the requested stay.”According to the HISA Authority, a stay would allow the defendants to “forgo rehearing petitions and proceed directly to filing a certiorari petition to minimize delay.”The HISA Authority's motion continued: “At a minimum, issuance of the mandate would sow chaos and confusion as State racing commissions (or the FTC) scramble to step in to enforce the governing HISA rules while racing occurs across the country.“In transitioning to the long-anticipated rollout of the now three-year-old regime, many States underwent substantial operational (and legal) changes–e.g., reducing their staff who worked on racetrack-safety and anti-doping issues; eliminating contracts with drug-testing laboratories; and reallocating funding. The Authority and its partners absorbed many of these personnel and duties. Accordingly, multiple States simply would not be in a position to take over enforcement of critical HISA rules–or would refuse.“The resulting 'Wild West' vacuum would communicate a perilous reality to would-be cheaters: 'nobody can enforce the rules, so go dope your horses to your heart's content,' at least until the States undergo massive transformations to fill the gap,” the motion stated.“Staying the mandate is also necessary to protect important comity concerns,” the HISA motion continued. “Plaintiffs have made clear, in this and other cases, that they seek to bring down HISA nationwide. As Plaintiffs have confirmed, it is already the case that HISA rules do not govern horseracing in any jurisdiction in [the Fifth] Circuit [because Texas is not running covered races and Louisiana races are exempted by federal court order in a different lawsuit].”The Fifth Circuit issued an expedited order July 14 that stated, “The Appellees' unopposed motion for stay of the mandate pending petition for writ of certiorari is GRANTED. If the petition is granted, the stay will continue until the Supreme Court's judgment is handed down. If the petition is denied, the stay will dissolve.”The post Fifth Circuit To Hold Off On Anti-Constitutionality Mandate Pending HISA Appeal To Supreme Court appeared first on TDN | Thoroughbred Daily News | Horse Racing News, Results and Video | Thoroughbred Breeding and Auctions.