A per curiam Supreme Court decision reinforcing that mandamus cannot be used to bypass the final judgment rule.
Allied Chemical Corp. v. Daiflon, Inc. is a shorter, per curiam Supreme Court decision, but it delivers a pointed reminder that continues to shape how lower courts evaluate mandamus petitions challenging interlocutory rulings.
The underlying dispute
The case arose after a court of appeals granted mandamus relief directing a district court to vacate an order granting a new trial, a ruling the Supreme Court found exceeded the proper scope of mandamus review.
The Supreme Court's core message
The Court's opinion emphasized that mandamus is not to be used as a substitute for the regular appellate process merely because a party believes a trial court committed error, however sincerely that belief is held, and however inconvenient the ordinary appeal process may be for the party seeking relief.
Why this decision matters for modern practice
Allied Chemical is frequently cited by courts denying mandamus petitions that, despite creative framing, essentially ask an appellate court to correct a trial court error immediately rather than waiting for the case to reach final judgment through the ordinary process.
The relationship to Kerr and other precedent
This decision reinforces the same line of reasoning found in Kerr and Will, discussed in a linked article in this section — collectively, these cases form a consistent body of Supreme Court precedent cautioning against using mandamus as a general-purpose early appeal.
The lesson for petitioners
Before filing a mandamus petition challenging a trial court ruling, it is worth honestly asking whether the underlying complaint is really about an extraordinary, irreparable harm — or whether it is, in substance, an ordinary disagreement that the regular appellate process is designed to address.
New trial orders and the limits of appellate supervision
A four-week antitrust trial ended with a jury verdict for Daiflon and an award of $2.5 million. The trial judge denied judgment notwithstanding the verdict but granted a new trial, citing evidentiary errors committed during the trial. Daiflon petitioned the Tenth Circuit, which issued a writ of mandamus directing the district court to reinstate the liability verdict and hold a new trial on damages alone.
The Supreme Court reversed summarily in Allied Chemical Corp. v. Daiflon, Inc., 449 U.S. 33 (1980) (per curiam). The grant of a new trial is committed to the trial judge's discretion, and a trial court's ordering of a new trial will rarely if ever justify issuance of the writ. The court of appeals had disagreed with a discretionary call and used mandamus to substitute its own judgment. Only exceptional circumstances amounting to a judicial usurpation of power justify that remedy, and a debatable evidentiary ruling is not one.
The boundary with the final judgment rule
The per curiam framed the question as one of appellate structure: interlocutory mandamus undermines the policy against piecemeal appellate review, and the new trial order was fully reviewable once the case reached final judgment. Before filing a petition, a party should be able to say why each ordinary route is closed.
| Route | Authority | When it is open |
|---|---|---|
| Appeal from final judgment | 28 U.S.C. § 1291 | After the case ends; the default answer to most interlocutory complaints |
| Certified interlocutory appeal | 28 U.S.C. § 1292(b) | Controlling question of law, substantial ground for difference of opinion, material advancement of the litigation; the district court certifies and the court of appeals may accept |
| Partial final judgment | Fed. R. Civ. P. 54(b) | Multiple claims or parties, with an express determination by the district court |
| Class certification appeal | Fed. R. Civ. P. 23(f) | Permissive appeal, sought within the deadline the rule sets |
| Mandamus | 28 U.S.C. § 1651; Fed. R. App. P. 21 | None of the above is adequate and the order amounts to a usurpation of power |
The category of rulings the writ will not reach
What Allied Chemical places out of reach is an entire class of decisions: evidentiary rulings, new trial and remittitur orders, scheduling, the ordinary run of discovery disputes, and the weighing of conflicting evidence. Disagreement with how discretion was exercised is not a clear and indisputable right to a different outcome. It is an appellate argument, and it keeps until final judgment.
That the Court decided the case per curiam, without argument, is itself part of the message: the rule was not treated as debatable. There is also a trap in the language petitioners commonly use. A party who characterizes a district court's ruling as an abuse of discretion has conceded that discretion existed, and discretionary orders are reviewable on appeal rather than correctable by writ.
Key points
- Allied Chemical Corp. v. Daiflon, Inc., 449 U.S. 33 (1980), was a per curiam reversal of a Tenth Circuit writ that had reinstated a jury verdict after a new trial was ordered.
- A trial court's grant of a new trial will rarely if ever justify mandamus, because the ruling is discretionary and reviewable after final judgment.
- The decision draws the line at usurpation of power: disagreement with a discretionary ruling is an appeal, not a writ.
- Before petitioning, a party should be able to explain why 28 U.S.C. § 1291, § 1292(b), Rule 54(b) and Rule 23(f) are all unavailable.
- Framing a complaint as an abuse of discretion concedes that discretion existed, which undercuts the clear-and-indisputable requirement.