JERRY E. SMITH, Circuit Judge:
Defendants Bobby Jindal, Governor of Louisiana; the Louisiana Department of Public Safety and Corrections; and various state officials (the "state") appeal a preliminary injunction and stay of execution granted to death-row inmate Christopher Sepulvado.1 Finding reversible error, we reverse the injunction and the stay.
I.
In 1993, Sepulvado was convicted and sentenced to death for the first-degree murder of his six-year-old stepson. His conviction and sentence were affirmed. State v. Sepulvado, 672 So.2d 158 (La.), cert. denied, 519 U.S. 934, 117 S.Ct. 310, 136 L.Ed.2d 227 (1996). He sought post-conviction relief in state and federal court. The federal district court denied habeas corpus relief, Sepulvado v. Cain, No. 00-596 (W.D.La. Aug. 9, 2002), and denied Sepulvado's application for a certificate of appealability. In a detailed opinion setting out the facts and proceedings, we denied Sepulvado's request for a certificate of appealability on six issues, Sepulvado v. Cain, No. 02-30909, 2003 WL 261769 (5th Cir.) (per curiam), cert. denied, 540 U.S. 842, 124 S.Ct. 110, 157 L.Ed.2d 76 (2003), then dismissed his successive habeas petition for want of jurisdiction, In re Sepulvado, 707 F.3d 550, 552 (5th Cir.2013), petition for cert. filed (May 8, 2013) (No. 12-10251).
On December 12, 2012, a state court issued a death warrant and set Sepulvado's execution for February 13, 2013. State law provides that "[e]very sentence of death ... shall be by lethal injection; that is, by the intravenous injection of a substance or substances in a lethal quantity into the body of a person convicted until such person is dead." La. R.S. 15:569(B) (2012). "Prior to 2010, the State of Louisiana used a three-drug procedure to execute inmates via lethal injection." Hoffman v. Jindal [Hoffman I], No. 12-796-JJB, 2013 WL 489809, at *1 (M.D.La. Feb. 7, 2013). Since 2010, the first drug in the procedure — sodium thiopental — has been unavailable. In December 2010, the state repealed the section of its administrative code enumerating the specific procedures to be followed for the lethal injection of those individuals sentenced to death.2
On December 20, 2012, death-row inmate Jessie Hoffman3 sued under 42 U.S.C. § 1983 alleging, among other claims, that the state's refusal to disclose the details of its execution protocol violates the Due Process Clause of the Fourteenth Amendment. "Counsel for the State has indicated that ... a single dose of pentobarbital will now be used to execute inmates. However, the State has refused to officially disclose what the protocol is until formal discovery procedures have been complied with." Hoffman I, 2013 WL 489809, at *1.
On February 6, 2013, the district court granted Sepulvado's January 23 motion to intervene in Hoffman's suit. The next day — less than a week before Sepulvado's scheduled execution — the court issued a preliminary injunction and stay, reasoning as follows:
"Fundamental fairness, if not due process, requires that the execution protocol that will regulate an inmate's death be forwarded to him in prompt and timely fashion." Oken v. Sizer, 321 F.Supp.2d 658, 664 (D.Md.2004). Fundamental fairness requires that the inmate be given meaningful and adequate notice of how his rights have been affected by the changes in the execution protocol. Sepulvado is entitled to review the full protocol itself.
Id. at *2.
II.
We begin by noting what is not at issue. Sepulvado does not challenge the legitimacy or legality of his death sentence, which has been upheld by every court that has considered it over the past two decades. "[C]apital punishment is constitutional.... It necessarily follows that there must be a means of carrying it out."4 In Baze, the Court explicitly approved lethal injection as a legal means of execution.5
Baze addressed Kentucky's three-drug protocol, but "a one drug protocol [is] also acceptable under the flexible Baze standard...." Thorson v. Epps [Thorson II], 701 F.3d 444, 447 n. 3 (5th Cir.2012), petition for cert. filed (Feb. 12, 2013) (No. 12-1010). Other federal courts of appeals agree that pentobarbital-only protocols comport with the Eighth Amendment's prohibition against cruel and unusual punishment.6 Indeed, the losing plaintiffs in Baze urged Kentucky to do what Louisiana has done: Adopt "a one-drug protocol that dispenses with the use of pancuronium and potassium chloride...."7
The district court did not reach Sepulvado's Eighth Amendment claim.8 Our review is thus limited to determining whether the court erred by issuing an injunction and stay on due-process grounds.
III.
Regarding the standard for an injunction,
A preliminary injunction is an extraordinary remedy that should only issue if the movant establishes:
(1) a substantial likelihood of success on the merits, (2) a substantial threat of irreparable injury if the injunction is not issued, (3) that the threatened injury if the injunction is denied outweighs any harm that will result if the injunction is granted, and (4) that the grant of an injunction will not disserve the public interest.
Byrum v. Landreth, 566 F.3d 442, 445 (5th Cir.2009) (quoting Speaks v. Kruse, 445 F.3d 396, 399-400 (5th Cir.2006)).
We review a preliminary injunction for abuse of discretion. See Janvey v. Alguire, 647 F.3d 585, 591-92 (5th Cir. 2011). "Despite this deferential standard, `a decision grounded in erroneous legal principles is reviewed de novo.'" Id. at 592 (quoting Byrum, 566 F.3d at 445). "As to each element of the district court's preliminary-injunction analysis, the district court's findings of fact are subject to a clearly-erroneous standard of review, while conclusions of law are subject to broad review and will be reversed if incorrect." Id. (internal quotation marks omitted).
IV.
"To assess the likelihood of success on the merits, we look to standards provided by the substantive law." Id. at 596 (internal quotation marks omitted). The district court determined that Sepulvado was likely to prevail on his claim that the Due Process Clause of the Fourteenth Amendment entitles him to prompt and detailed disclosure of Louisiana's most recent execution protocol. Hoffman I, 2013 WL 489809, at *2. The only authority the district court cited to support its conclusion was Oken v. Sizer, 321 F.Supp.2d at 664, in which the Supreme Court, 542 U.S. 916, 916, 124 S.Ct. 2868, 159 L.Ed.2d 290 (2004), swiftly — and summarily — vacated the stay.9
At least one of our sister circuits has rejected a similar claim based on Oken. Less than twenty-four hours before the scheduled execution of inmate Beaty, Arizona informed him that it intended to substitute pentobarbital for sodium thiopental in its lethal injection protocol. Beaty v. Brewer [Beaty I], 791 F.Supp.2d 678, 682-83 (D.Ariz.2011). Beaty alleged that the "failure to timely notify him of the drug substitution violates his right to due process under the Fourteenth Amendment because he lacks sufficient time to review the protocol change, as well as his medical records, to determine whether there are any constitutional concerns with the new drug." Id. at 681. The district court disagreed:
In his motion for injunctive relief, Plaintiff relies on Oken in support of his assertion that he has a right to reasonable notice of protocol changes so that he can ensure such changes comport with constitutional requirements. However, this Court cannot rely on one district court's unsupported assertion that capital plaintiffs have such a due process right, especially in view of the fact that the United States Supreme Court vacated the stay of execution granted by the district court in Oken....
Moreover, other than the district court order in Oken, Plaintiff cites no authority to support his allegation that the Due Process Clause provides a right to review protocol changes and attempt to challenge them. Other courts to address this issue have found no such authority. See Clemons v. Crawford, 585 F.3d 1119, 1129 n. 9 (8th Cir.2009) (noting lack of authority indicating due process right to probe into backgrounds of execution personnel); Powell v. Thomas [Powell I], ... 784 F.Supp.2d 1270, 1282-83 ... (M.D.Ala.... 2011) (finding no authority for proposition that condemned inmate has due process right to receive notice and an opportunity to be heard regarding substitution of pentobarbital).
Given the lack of authority to support Plaintiff's procedural due process violation, the Court finds that he has failed to establish a likelihood of success on the merits of that claim to notice....
Id. at 685-86 (citation omitted). The Ninth Circuit affirmed "[f]or the reasons expressed by the district court...." Beaty v. Brewer [Beaty II], 649 F.3d 1071, 1072 (9th Cir.2011) (per curiam) (emphasis added).
Sepulvado relies heavily on Arthur v. Thomas, 674 F.3d 1257, 1263-64 (11th Cir. 2012) (per curiam), in which the court reversed the dismissal of a claim that Alabama had materially deviated from its execution protocol. Arthur is inapposite, because the court grounded its decision in the Eighth Amendment and the Equal Protection Clause. See id. at 1262, 1263. Arthur also alleged that the "Alabama's policy of keeping information about its lethal injection procedure secret violates the Due Process Clause...." Id. at 1259. The court did not reach that claim and expressly refrained from requiring Alabama to produce its execution protocol.10 We agree with the state that nothing in Arthur overruled a prior holding from the same court rejecting an intervenor's claim — made pursuant to the Eighth Amendment rather than the Fourteenth — that he possessed a "broad ... right to know the details of his execution in order to ensure proper oversight and avoid uncertainty that unnecessarily creates anxiety...."11
In summary, no appellate court has recognized the due-process claim on which the district court a quo granted relief; we decline to be the first. Sepulvado's assertion of necessity — that Lousiana must disclose its protocol so he can challenge its conformity with the Eighth Amendment — does not substitute for the identification of a cognizable liberty interest.12 According to the district court, "[i]t is axiomatic that... an inmate who is to be executed cannot challenge a protocol as violative of the 8th Amendment until he knows what that protocol contains." Hoffman I, 2013 WL 489809, at *1. We disagree.13 Adopting the district court's reasoning would frustrate "the State's significant interest in enforcing its criminal judgments...." Nelson v. Campbell, 541 U.S. 637, 650, 124 S.Ct. 2117, 158 L.Ed.2d 924 (2004) (citation omitted). Courts are not supposed to function as "boards of inquiry charged with determining `best practices'...." Baze, 553 U.S. at 51, 128 S.Ct. 1520 (plurality opinion).
Despite Louisiana's concealment of its protocol, Sepulvado has managed to assert a litany of specific cruel-and-unusual-punishment claims.14 Other inmates have survived motions to dismiss and have obtained discovery on the strength of similar, unsubstantiated allegations.15 In later proceedings, Sepulvado himself has overcome the state's contention that his complaint failed to state a claim. See Hoffman II, 2013 WL 1637244, at *3-*6.
There is no violation of the Due Process Clause from the uncertainty that Louisiana has imposed on Sepulvado by withholding the details of its execution protocol. Perhaps the state's secrecy masks "a substantial risk of serious harm,"16 but it does not create one. Having failed to identify an enforceable right that a preliminary injunction might safeguard, Sepulvado cannot prevail on the merits.17
The injunction, which is "grounded in erroneous legal principles," is an abuse of discretion. Janvey, 647 F.3d at 592 (quoting Byrum, 566 F.3d at 445). "Because we have determined that [Sepulvado] cannot show a substantial likelihood of success ..., we need not address [the state]'s additional arguments regarding the other necessary elements for preliminary injunctive relief." Our ruling on the initial element is sufficient for reversal. "The holding on the initial element is sufficient to vacate the injunction." La Union Del Pueblo Entero v. Fed. Emergency Mgmt. Agency, 608 F.3d 217, 225 (5th Cir.2010).
V.
"We review a district court's grant of a stay of execution for abuse of discretion." Adams v. Thaler, 679 F.3d 312, 318 (5th Cir.), cert. denied, ___ U.S. ___, 132 S.Ct. 1995, ___ L.Ed.2d ___ (2012). "[A] stay of execution is an equitable remedy. It is not available as a matter of right, and equity must be sensitive to the State's strong interest in enforcing its criminal judgments without undue interference from the federal courts." Hill v. McDonough, 547 U.S. 573, 584, 126 S.Ct. 2096, 165 L.Ed.2d 44 (2006). "As we read Hill, a plaintiff cannot wait until a stay must be granted to enable him to develop facts and take the case to trial — not when there is no satisfactory explanation for the delay." Reese v. Livingston, 453 F.3d 289, 291 (5th Cir.2006).
VI.
"In White v. Johnson [, 429 F.3d 572 (5th Cir.2005) (per curiam)], [we] denied a motion for a stay, explaining that the inmate had been sentenced to death for over six years and `only now, with his execution imminent, has decided to challenge a procedure for lethal injection that the State has been using for his entire stay on death row.'"18 Sepulvado has been on death row for more than twenty years. The State maintains that his intervention in Hoffman's suit — less than a month before his scheduled execution — was impermissibly dilatory. The district court disagreed, concluding that
there is a satisfactory explanation for the delay. Sepulvado has been trying to determine what the protocol is for years and the State will not provide this information. It is also factually distinguishable from White because in White, the inmate was challenging a known procedure that had been in place for the duration of his death row stay. Here, ever since 2010, the procedure has been unknown.
Hoffman I, 2013 WL 489809, at *1.
As the district court observed, Louisiana's repeal of its lethal-injection protocol — which forms the basis of Sepulvado's due-process claim — occurred two years before he challenged the state's secrecy on the eve of his execution.19 Any harm accrued in December 2010, and Sepulvado has not explained his failure to bring a claim before December 2012.20 The district court abused its discretion by granting Sepulvado's untimely motion for a stay. Even assuming arguendo that the motion was timely, there is no equitable basis for further delay, because Sepulvado is not entitled to injunctive relief.21
The preliminary injunction and stay of execution are REVERSED.
