Amicus Curiae Briefs Are Quietly Turning Judges into Legislators

The phrase sounds harmless. "Amicus curiae" means friend of the court. But the modern amicus brief is not much of a friend. It has become a litigation lobbyist, an instrument by which people who are not parties to a case, who have suffered no injury, and who are accountable to no one, shape how judges decide the Constitution's meaning.

Most commentary on amicus briefs misses the deeper problem. Critics complain that there are too many of them, or that they are too long, or that interest groups coordinate them to manufacture an illusion of consensus. Those are real issues. But they are symptoms. The real problem is constitutional. The amicus brief as it now operates is alien to the judicial office the Founders designed.

Article III extends the judicial power to cases and controversies. A court is not a legislature. It does not exist to survey public opinion, measure institutional support, or choose the most popular outcome. It exists to decide the legal rights of the parties before it, according to law. Everything about the modern amicus regime pushes in the other direction.

The Original Office

In the common law tradition, an amicus curiae was exactly what the Latin suggested: a neutral lawyer, sometimes summoned by the judge, who helped the court understand a point of law that the parties had not addressed. He was not an advocate. He was not retained by a party to win. He was an aid to the judge, not a soldier in someone else's cause.

That made sense because of what a court is. The parties have standing because they have actually been injured. They bring a concrete dispute, with a factual record developed under the rules of evidence. The court decides that dispute according to the law and the Constitution as written. Nothing in that design gives strangers a formal role simply because they feel strongly about the outcome.

Alexander Hamilton put the point precisely in Federalist 78. The judiciary has no influence over either the sword or the purse. It has neither force nor will, but merely judgment. A court's legitimacy comes from deciding legal questions according to fixed law, not from weighing the preferences of whichever interest group can print the most paper. Hamilton went further. The interpretation of the laws is the proper and peculiar province of the courts. That is an act of judgment, not of policymaking.

A true friend of the court helps the judge perform that act. He identifies a precedent the parties missed. He explains the original public meaning of a statutory term. He clarifies a point of law. He does not bring new facts, new policy arguments, or new pressure. He is a friend of the court, not a friend of a cause.

The Modern Mutation

Today the practice is almost inverted. In a major Supreme Court term, hundreds of amicus briefs pour in. A single high-profile case can draw well over a hundred of them. They are filed by corporations, trade associations, advocacy organizations, former officials, academics, state governments, and coalitions of all three. Some are genuinely useful. Many are not.

The modern amicus brief is not neutral. It is advocacy, often carefully coordinated to signal political support for one side. It may bring arguments and factual claims that appear nowhere in the trial record. It may rely on social science studies, opinion polls, economic forecasts, or predictions about consequences that have never been tested by cross-examination or the rules of evidence. A judge is not equipped to verify a survey buried in a hundred page brief. He is being asked to rely on something that was never admitted as evidence.

Worse, judges sometimes treat these briefs as though they carry weight. A justice may cite a brief signed by a long list of former officials or constitutional law professors. But a brief is not evidence. It is not law. It is advocacy dressed up as authority. If the thing that makes it persuasive is the prestige of its signatories, that is an appeal to authority, not to the Constitution.

That is not amicus curiae. It is amicus causae, friend of a cause.

Three Constitutional Injuries

The modern amicus regime quietly undermines three first principles of a constitutional republic.

First, it erodes standing. We have long held that courts decide concrete disputes between injured parties. That is what keeps the judiciary within its proper bounds. But when any group can file a brief and be taken seriously, the case is no longer just a dispute between parties. It becomes a vehicle for interest groups to litigate by proxy. People who could not sue on their own because they have no standing get a formal way to shape constitutional law anyway. The injury requirement, which is supposed to keep courts out of abstract policy fights, is bypassed through the side door of the amicus brief.

Second, it turns the judiciary into a lobbying target. Congress is supposed to be lobbied. That is what representative government does. People press their interests, and elected officials weigh them. But the judiciary is deliberately insulated from that. It is the counter-majoritarian branch in a republic of laws. When interest groups flood the Court with briefs designed to show that their side has more institutional support, they are trying to make the Court behave like a legislature. The brief is no longer about what the law means. It is about who has more friends.

Third, and most dangerously, it invites judicial activism. An originalist judge asks one question: what did the text mean when it was adopted? The amicus industrial complex often asks a different question: what outcome would be best for the country, the economy, or the cause? Once a judge starts reasoning from policy briefs and social science data instead of text and history, he has stopped interpreting law and started legislating. The amicus brief becomes an invitation to rule on consequences rather than meaning, on desired results rather than original public meaning.

Thomas Sowell taught us to judge policies by incentives and results, not intentions. People defend amicus briefs because they intend to give judges more information. But the result is that judges receive a curated stream of advocacy from interested parties, and the louder and better funded the interest, the more information the court receives. That is not neutral knowledge. That is organized pressure.

Henry Hazlitt's one lesson applies with precision. The visible benefit is a judge who looks well informed. The unseen cost is a judiciary that gradually becomes another political arena, and a rule of law that is replaced, case by case, by a contest of interest groups.

The Usual Defense Falls Short

The common defense is that amicus briefs provide valuable expertise and help courts understand complex issues. I do not doubt the good intentions behind many of them. But the argument mistakes output for process.

If a court needs expertise, it can appoint a neutral expert. It can ask the parties to address a point of law. It can order supplemental briefing. It does not need unsolicited advocacy from strangers whose arguments and facts are not in the record. A true friend of the court is someone the court asks to help, not someone who buys a ticket into the case.

Another defense is that filing an amicus brief is a form of free speech. Of course people have a right to speak, and to file their own lawsuits when they have standing, and to petition the political branches. But formally participating in someone else's case is not a First Amendment right. It is a privilege granted by the court, and it should be exercised under rules that protect the integrity of the judicial process. Nobody's freedom of speech is violated when a court declines to read a stranger's unsolicited brief.

Restoring the True Friend of the Court

I am not calling for the abolition of amicus briefs. I am calling for their return to their original office.

The rule should be simple. A court should accept an amicus brief only when the brief does something a genuine friend of the court would do: identify precedent the parties missed, explain the original public meaning of a text, or clarify a pure point of law. It should not inject facts outside the record. It should not argue policy. It should not tell the court which side has more prestigious supporters.

Unsolicited briefs should be rare, not routine. They should be accepted only if the court requests them or if they address a genuinely underdeveloped question of law in the parties' own briefs. No sign-on campaigns. No factual claims that were never tested. No arguments that the outcome should depend on which side can assemble the longest list of signatories.

Justices should also stop citing amicus briefs as if they were authority. If an argument is sound, it will stand on the Constitution and the record. If it appears only in an amicus brief and not in the parties' own filings, the court should be cautious, because it is being asked to decide on the basis of something that was never placed in evidence.

When Hamilton said the judiciary has neither force nor will but merely judgment, he was not describing a branch that would open its docket to every interested group with a printing budget. He was describing a branch that decides cases according to law.

The friend of the court ought to be a friend of the law. We should insist on that distinction again, before the amicus brief completes its transformation from a neutral aid into an unelected lobbying channel for whoever can make the most noise.

That is the real fight. It is not about whether judges receive enough information. It is about whether we still have a judiciary at all, or merely another legislature in robes.