4th Circuit May Shift Preliminary Injunction Analysis Approach

A preliminary injunction can determine the practical winner of a lawsuit long before anyone reaches trial. It may stop a government program, suspend a business practice, protect confidential information, or preserve the status quo while the attorneys continue converting coffee into motions.

That is why the Fourth Circuit’s 2025 decision in American Federation of Teachers v. Bessent attracted immediate attention. The panel described a “multiplicative problem” that could make preliminary relief substantially harder to obtain when plaintiffs must prevail on several independent legal issues. Instead of considering likelihood of success in ordinary qualitative terms, the opinion suggested that courts should account for how multiple probabilities combine.

For several months, the decision appeared capable of reshaping preliminary injunction analysis throughout Maryland, North Carolina, South Carolina, Virginia, and West Virginia. The story did not end there, however. In April 2026, the en banc Fourth Circuit expressly abrogated the probability-multiplication portions of AFT and restored the traditional approach required by Winter v. Natural Resources Defense Council.

What Is a Preliminary Injunction?

A preliminary injunction is a temporary court order issued before a case receives a final judgment. Under Rule 65 of the Federal Rules of Civil Procedure, it may require a party to stop certain conduct or, in appropriate circumstances, take affirmative action while litigation continues.

The remedy is preliminary because the court is not conclusively deciding liability. Judges usually work with an abbreviated record, disputed facts, and legal questions that have not received full discovery or trial treatment. The purpose is generally to prevent injuries that cannot be adequately repaired later and to preserve meaningful relief until the case can be resolved.

That temporary label should not be mistaken for insignificance. An injunction may remain effective for months or years. In fast-moving disputes involving elections, trade secrets, public policies, or private data, temporary relief can have consequences as substantial as a final judgment.

The Traditional Four-Factor Test

The controlling framework comes from the Supreme Court’s 2008 decision in Winter v. Natural Resources Defense Council. A plaintiff seeking a preliminary injunction must make a clear showing that:

1. The plaintiff is likely to succeed on the merits.
2. The plaintiff is likely to suffer irreparable harm without preliminary relief.
3. The balance of equities favors an injunction.
4. An injunction serves the public interest.

A preliminary injunction is an extraordinary remedy, not something awarded automatically because a complaint sounds serious. The plaintiff carries the burden on every required factor. A court may deny relief after finding that one essential factor is missing, even when the remaining arguments are compelling.

How Winter Changed Fourth Circuit Law

Before Winter, Fourth Circuit courts frequently relied on the balance-of-hardships approach associated with Blackwelder Furniture Co. v. Seilig Manufacturing Co. That framework allowed a particularly strong showing of hardship to compensate for a weaker showing on the merits.

In The Real Truth About Obama, Inc. v. FEC, the Fourth Circuit recognized that Blackwelder could not survive Winter. The four requirements had to be independently satisfied. A plaintiff could no longer place an enormous irreparable-harm argument on one side of the scale and hope it would perform the legal equivalent of lifting the entire courthouse.

How American Federation of Teachers v. Bessent Reframed the Inquiry

American Federation of Teachers v. Bessent arose after Executive Order 14158 established the U.S. DOGE Service and directed federal agencies to create internal DOGE teams. The Department of Education, Department of the Treasury, and Office of Personnel Management granted DOGE-affiliated personnel access to agency information systems.

Unions, professional organizations, veterans, and other individuals sued federal officials. They argued that allowing DOGE personnel to access sensitive personal information violated the Privacy Act and Administrative Procedure Act. A Maryland federal court entered a preliminary injunction limiting that access.

On August 12, 2025, a divided Fourth Circuit panel vacated the order. The majority concluded that the plaintiffs had not demonstrated a sufficient likelihood of overall success because their theory depended on resolving several potentially dispositive questions in their favor.

The “Multiplicative Problem”

The panel reasoned that when a plaintiff must win several independent issues, the probability of ultimate success may be lower than the probability of winning any single issue. Its illustrative arithmetic was simple: if a plaintiff had a 75% chance of winning each of five independent issues, the probability of winning all five would be approximately 24%.

The plaintiffs faced questions concerning Article III standing, final agency action under the APA, the availability of another adequate remedy, and the Privacy Act’s need-for-the-record exception. The panel did not definitively decide every question against them. Instead, it concluded that the accumulated uncertainty made overall success unlikely.

This approach threatened to make complex litigation structurally harder for plaintiffs. A party might appear favored on every individual issue yet become an aggregate underdog once the probabilities were multiplied. Defendants, meanwhile, would need to prevail on only one independently dispositive issue.

Why the Probability Approach Drew Criticism

Judge Robert King’s dissent argued that the majority had created a heightened standard beyond Winter. In his view, the district court had already examined each contested issue and found that the plaintiffs were likely to prevail. Requiring an “extremely high” probability on every component added a burden the Supreme Court had never imposed.

The framework also presented practical problems. Judges rarely possess evidence allowing them to distinguish reliably between a 70% and 75% chance of success on a legal question. Novel statutory issues do not arrive with betting lines attached.

Nor are legal issues always statistically independent. A ruling on standing may depend on the court’s understanding of the alleged statutory violation. Two defenses may rest on the same interpretation of agency authority. Multiplying those supposedly separate probabilities can double-count the same uncertainty.

The model nevertheless highlighted a legitimate litigation reality: a case with five essential weak links may be less likely to succeed than a case with one straightforward issue. The controversy concerned whether that commonsense observation should become a formal mathematical method.

The En Banc Fourth Circuit Rejects the Mathematical Test

The uncertainty was resolved in American Federation of State, County and Municipal Employees v. Social Security Administration. That related case challenged DOGE personnel’s access to sensitive Social Security Administration records. Because the dispute closely resembled AFT, the Fourth Circuit considered it en banc.

On April 10, 2026, the full court expressly disavowed any suggestion that district judges should assign numerical probabilities to separate issues and multiply them. The court described preliminary injunction analysis as an exercise of equity rather than a mechanical algorithm.

The en banc opinion identified several weaknesses in the mathematical approach:

• Legal probabilities generally cannot be quantified with meaningful precision.
• AFT did not adequately define when legal issues are truly independent.
• The model did not address conditional probability or overlapping arguments.
• It risked imposing an additional hurdle in complicated cases.
• It could distract courts from the traditional equitable inquiry required by Winter.

The court held that plaintiffs must still show they are likely to succeed on their lawsuit. They do not, however, face a different standard merely because their case contains multiple claims, defenses, or jurisdictional questions. All contrary statements in AFT were abrogated.

Why the Injunction Was Still Vacated

Rejecting the multiplicative approach did not save the Social Security injunction. The en banc court’s judgment vacated it and remanded the case, although the 88-page decision contained several opinions and no single rationale commanded every judge’s agreement.

The lead opinion concluded that the plaintiffs had Article III standing because allegedly unauthorized access to sensitive personal information bore a close relationship to the traditional harm of intrusion upon seclusion. It nevertheless determined that the plaintiffs had not established irreparable harm under Winter because damages or a later reparative injunction might provide adequate relief.

Separate concurring opinions reached the same judgment through somewhat different reasoning, while multiple judges dissented. The fractured result is an important reminder: a plaintiff can win a significant doctrinal question and still lose the requested injunction on another factor.

What the Current Rule Means for Litigants

The Fourth Circuit preliminary injunction standard is once again unmistakably qualitative. Courts should evaluate the strength of the plaintiff’s case as a whole without inventing numerical percentages. Complexity remains relevant, but it is not an automatic penalty.

For Parties Seeking an Injunction

Applicants should identify every threshold and merits issue that could independently defeat relief. Standing, jurisdiction, reviewability, statutory preclusion, causation, and available remedies cannot be tucked into a footnote and asked to behave themselves.

The evidence of irreparable harm deserves equal attention. Establishing a concrete injury for standing does not necessarily establish irreparable harm. A plaintiff must explain why damages, final declaratory relief, data destruction, or a later permanent injunction would be inadequate.

For Parties Opposing an Injunction

Defendants may no longer argue that legal uncertainties must be assigned percentages and multiplied. They can still emphasize that the plaintiff must prevail on several essential questions and that serious weaknesses undermine the required clear showing.

An opposition should also examine remedies. If financial compensation or corrective relief would repair the alleged injury, the second Winter factor may defeat the motion without requiring the court to resolve every unsettled merits question.

For District Courts

District judges should make specific findings on the issues necessary to support relief. Courts retain flexibility to organize their analysis sensibly, but the decision must demonstrate faithful application of Winter. An injunction must also comply with Rule 65 by stating its terms specifically and describing the restrained conduct in reasonable detail.

Experience-Based Lessons from Preliminary Injunction Disputes

Experiences from emergency litigation reveal that the outcome often depends less on the number of arguments than on how clearly the movant connects facts, law, harm, and requested relief. A rushed filing may contain a formidable stack of declarations and still leave the judge wondering what injury will occur next Tuesday. Volume is not the same as proof; sometimes it is merely heavier.

Consider a company seeking to prevent a former employee from disclosing trade secrets. The company may possess a strong contract claim, evidence that confidential files were downloaded, and messages suggesting that a competitor wants the information. Its motion becomes much stronger when it identifies the particular secrets, explains why disclosure cannot be reversed, and proposes a narrowly tailored order. Asking the court to prohibit the former employee from using anything learned during ten years of employment is more likely to trigger concerns about fairness and enforceability.

Government-policy cases present a different experience. Plaintiffs may argue that a new rule threatens constitutional rights or unlawfully exposes private information. Yet standing, sovereign immunity, final agency action, statutory review provisions, and the scope of relief can all become threshold disputes. The temporary AFT framework encouraged defendants to divide those questions into as many “independent” obstacles as possible. After the 2026 en banc ruling, the better practice is to explain how those issues affect the case’s overall legal strength without pretending each comes with a certified percentage.

The irreparable-harm showing is where many otherwise persuasive motions stumble. A business may predict lost revenue but fail to explain why money damages would be unavailable. An employee may describe severe professional disruption without showing why reinstatement or back pay could not provide relief. A privacy plaintiff may establish a genuine invasion yet still need to demonstrate why later deletion, damages, or another corrective order would be inadequate.

Another recurring lesson involves requested scope. Judges are more receptive when the proposed injunction addresses the proven threat and leaves lawful conduct untouched. In the Social Security litigation, debates over anonymized data, training, background checks, particularized access, and data destruction demonstrated how much the design of relief matters. An injunction is not simply an on-off switch; it can be tailored with exceptions, conditions, deadlines, and reporting requirements.

Finally, appellate preparation should begin before the district court hearing. Preliminary injunction appeals move quickly, and appellate courts review legal conclusions closely even while applying abuse-of-discretion review to the ultimate decision. Parties should build a coherent evidentiary record, preserve objections, offer a precise proposed order, and explain every Winter factor. Emergency litigation rewards preparation performed before the emergency announces itself.

Conclusion

American Federation of Teachers v. Bessent briefly signaled a major shift in Fourth Circuit preliminary injunction analysis by translating likelihood of success into compounded probability. The en banc Fourth Circuit has now rejected that experiment. Courts must apply Winter without numerical multiplication or an extra complexity penalty.

The practical lesson remains demanding. Plaintiffs must present a clear, integrated case on likely success, irreparable harm, the equities, and the public interest. Defendants need only expose a decisive weakness in one required factor. The calculator may be gone, but the high bar is very much still standing.

Note: This article provides general legal information and reflects decisions available through July 2026. It is not legal advice and should not replace advice from qualified counsel regarding a particular dispute.