If you searched Amicus brief law firms Perkins Coie, you are probably trying to understand one or both of these questions:
How Perkins Coie utilizes Amicus briefs (who they file for, what type of cases, and what that tells us about their appellate works).
What explains the barrage of law firms and legal entities that have filed Amicus briefs on the litigations against Perkins Coie during the 2025 executive order battles.
That’s what I’ll help you with. I will answer both questions for you, Perkins Coie as a frequent Amicus brief filer and Perkins Coie as a high-profile recipient of Amicus patronage, practically and factually based on the data you provided.
I will not avoid the more human context of this research. I understand how these topics can be laden with dates and docket entries, and how they can obscure the important elements of what the legal community treats as business as usual and what it treats as a five alarm fire.
Table of Contents
What Is An Amicus Brief?
An Amicus brief (for short amicus curiae, a friend of the court) is a submission from a non-party to the case, who wants the court to consider their point of view.
Imagine that your neighbour is arguing with the city over whether a new zoning rule is legal. You aren’t part of the lawsuit. But you own property on the same street, so you know how the rule works in real life. You write a letter to the judge to tell him or her something that the court might not see.
That’s the attitude, but in federal appeal courts and the Supreme Court, these “letters” are generally substantial, heavily cited briefs authored by experienced appellate lawyers.
That’s where law firms come in.
Why Perkins Coie Is A Popular Choice For Amicus Brief Law Firms
People look for this phrase because Perkins Coie is involved in both sides of the amicus world:
That second portion is strange. Law firms don’t normally get together in large numbers unless they think there is more at risk than just one party’s disagreement.
Notable Amicus Briefs Filed By Perkins Coie
Perkins Coie has an established practice for appeals and complex litigation, and amicus briefs are one of the tools available to them when a client’s interest may be impacted by a case, even when they are not a named litigant.
These are the two examples you provided and their significance.
1. Gun Regulation And Ghost Gun Litigation
In August 2023, an amicus brief was filed by Perkins Coie New York litigation team regarding federal regulation of ghost guns.
On behalf of 16 major cities in the U.S. and Prosecutors Against Gun Violence in a case pending before the U.S. Court of Appeals for the Eighth Circuit.
Why that’s a textbook example of an amicus brief:
If you have been privy to a court dealing with technical questions, like the sale, assembly, and trafficking of non-serialized weapon parts, you will understand the value of an amicus brief.
2. The Supreme Court And Laws About Content Moderation
In December 2023, Perkins Coie filed an amicus brief before the U.S. Supreme Court on behalf of the Marketplace Industry Association, Etsy, and OfferUp. They were trying to get the Court to overturn Texas and Florida statutes that would limit how digital platforms can moderate content.
Why this kind of amicus petition happens a lot in digital and platform cases:
In daily language, it’s like a mall being told it can’t take down a booth that sells stolen items because the owner of the booth says they have a right to be there. Moderation is what makes marketplaces work.
When Perkins Coie files papers like this, it means that their clients want appellate courts to appreciate the real-world effects, not simply the legal theory.
Perkins Coie and the Impact of Amicus Briefs: The 2025 Turning Point
Next came the 2025 litigation and its wave of amicus support, which drove a significant volume of searches.
The Perkins Coie Executive Order And Its Surge Of Amicus Briefs
In March 2025, you noted that President Donald Trump issued Executive Order 14230, widely described as targeting the firm. The order allegedly imposed sanctions that included restrictions affecting Perkins Coie’s ability to operate normally, such as limiting access to federal buildings and suspending or revoking security clearances.
The case that followed was Perkins Coie LLP v. DOJ.
Here’s the key point: many in the legal profession viewed the order not as a routine procurement or security policy, but as retaliation tied to Perkins Coie’s past representation of political opponents. That’s the kind of allegation that makes lawyers (even competing lawyers) sit up straighter.
Because if a law firm can be punished for who it represents, then representation stops being a right and starts being a risk calculation. That’s not a small shift. That’s a structural one.
I remember the first time I really understood this dynamic (not in court, just as a person reading and trying to make sense of it); it felt like realizing the referee could start penalizing the defense attorney for arguing too well. Once that door opens, the game changes, even if you never liked the team being defended.
April 2025: Over 800 Law Firms Support Perkins Coie
In April 2025, over 800 law firms filed or joined amicus briefs supporting Perkins Coie in its challenge to the executive order.
That number alone is extraordinary.
Law firms aren’t famous for doing things in packs. They compete. They poach talent. They fight over clients. So when hundreds of them align on a principle, it’s usually because they believe the precedent could hit everyone.
Who Organized the Major Law Firm Amicus Effort?
Several firms played central organizing or leadership roles in the amicus filings:
And the signatories included major firms, among them several Am Law 100 names you listed, such as:
The takeaway: this wasn’t a niche group. This was the mainstream legal establishment, in big numbers, saying: this is not okay.
Legal Organizations and Coalitions Filing Amicus Briefs
It wasn’t only private firms. A broad range of legal and civil rights organizations also filed or joined briefs.
ACLU Coalition And Other Advocacy Groups
You noted that the American Civil Liberties Union (ACLU) led a coalition of 11 legal advocacy groups, including:
That’s a striking mix. Those organizations don’t always agree on policy. But amicus coalitions like this sometimes form around a shared constitutional concern—especially where government retaliation and speech/association issues are in play.
Bar Associations Weighed In
You also noted that the New York City Bar Association organized a brief signed by metropolitan bar associations from Los Angeles, Chicago, Philadelphia, and Boston.
This category matters because bar groups tend to speak in the language of institutional integrity: independence of counsel, the rule of law, and norms that keep the adversarial system functional.
Legal Defense Fund (LDF)
The Legal Defense Fund (LDF) filed a brief arguing that the order threatened the independence of the legal profession.
21 State Attorneys General
A coalition of 21 Attorneys General, led by California’s Rob Bonta and Washington’s Nick Brown, filed in support.
When state AGs show up as amici, it adds political and governmental weight, not just lawyer consensus, but state law enforcement/state legal leadership believes this is dangerous.
The Competitor Framing: An Unprecedented Abuse of Executive Power
You referenced a competitor-style passage, noting:
Even if you never read another line about this topic, that’s the essence of why the amicus pile-on happened: a large swath of the legal community believed constitutional boundaries were being tested in a way that threatened the profession’s independence.
Outcome: Judge Howell’s May 2, 2025, decision
According to the information you provided, on May 2, 2025, Judge Beryl Howell (U.S. District Court for the District of Columbia) ruled in favor of Perkins Coie, finding the executive order violated the First, Fifth, and Sixth Amendments and permanently enjoining its enforcement.
That’s a clean endpoint for the story, but it also explains why the search term persists: people want to know who showed up, why they showed up, and what it means going forward.
Because the next time a similar executive action appears, against a different firm, or a different profession, courts and litigants will remember the scale of this response.
What This Means For Looking Into Law Firms And Amicus Briefs
Here are some useful tips if your main query is “What does this tell me about Perkins Coie or other firms that do a lot of appeals?”
1. Amicus work signals influence beyond the named parties
Perkins Coie’s amicus briefs in areas like gun control and platform moderation highlight how the firm helps shape legal theory when clients are affected in a big way but not directly.
2. The 2025 amicus increase was based on precedent, not popularity
The rush of support didn’t mean that everyone agreed with every Perkins Coie client or position. It was about fighting back against what many thought was the government’s punishment of legal representation.
3. Keep an eye on the people in charge
When you see names like Munger Tolles and Eimer Stahl working together on a brief for more than 500 firms, it means that experienced lawyers think there is a systemic problem that needs to be dealt with by everyone.
FAQs
Q. Was Perkins Coie only a filer of amicus briefs, or also supported by them?
Both. Perkins Coie frequently files amicus briefs for clients; in 2025 it became the subject of many amicus briefs supporting it in litigation.
Q. What was the key legal challenge in Perkins Coie LLP v. DOJ?
The lawsuit challenged an executive order that allegedly sanctioned the firm (including access restrictions and clearance issues), and argued to violate First, Fifth, and Sixth Amendment rights.
Q. How big was the amicus response?
You provided that 800+ firms filed or joined amicus briefs supporting Perkins Coie, with a major coalition brief joined by 500+ firms.
