The Core Prohibition

The Core Prohibition

Rule 1.12(a) forbids a lawyer to “represent anyone in connection with a matter in which the lawyer participated personally and substantially” as a judge or other adjudicative officer, as a law clerk to such a person, or as an arbitrator, mediator, or other third-party neutral.¹ That one sentence has three working parts. The trigger is a matter the lawyer handled in a covered role with real involvement. The breadth is the word “anyone,” which makes the bar follow the matter and ignore the client's side. The exit is informed consent from all parties to the proceeding, confirmed in writing, and paragraph (d) adds a separate exception for an arbitrator selected as a partisan of a party.² The sections after this one take up the covered roles and the meaning of personal and substantial participation. This section shows how the bar is shaped and why.

The second question does the most work in practice, because the bar attaches to a particular matter, and sharing a party or a courthouse with the earlier case does not trigger it. Rule 1.11(e), the parallel rule for former government lawyers, defines “matter” as “any judicial or other proceeding, application, request for a ruling or other determination, contract, claim, controversy, investigation, charge, accusation, arrest or other particular matter involving a specific party or parties.”³ Professors Hazard and Hodes read that definition as separating matters of general policy from “specific matters involving identifiable parties and particularized facts.”⁴ Read against that definition, “a matter” in Rule 1.12(a) means a particular dispute among identified parties, not a general familiarity with a party, a court, or a subject. The limit makes sense. A neutral who handled a dispute may be suspected of handling it with an eye on future work, or of carrying inside knowledge of it into private practice, and neither suspicion has anything to attach to when the new engagement is a different controversy. The limit also keeps judicial service from becoming costly, because a former judge remains free to represent clients against parties once judged in unrelated disputes.

James v. Mississippi Bar shows the bar at work on a single dispute. James, a former judge, later represented a party in a matter in which James had participated substantially on the bench. A separate opinion found that the representation “unequivocally violated” Rule 1.12, stated that a former judge “should have been keenly aware of this conflict,” called the principle “elementary,” and would have imposed a ninety-day suspension. The Chief Justice joined that opinion, and Justice Randolph joined in part.⁵ The opinion states the prohibition in terms of the matter and the former judge's participation in it. It does not ask which side the party occupied.

The parallel government-lawyer rule gives the two participation words a ready meaning, which the sections below test against judges, clerks, and neutrals. Under Rule 1.11(a), “personally” means direct participation in the matter, not mere service in the same office as others who handled it, and “substantial” means more than routinely forwarding a document or taking a purely ministerial action that involves no exercise of discretion.⁶

The breadth of Rule 1.12(a) is its most distinctive feature. Paragraph (a) says “anyone,” and one court's summary of the rule says the same: a former judge “may not represent anyone in connection with a matter” in which the judge “participated personally and substantially as a judge.”⁷ Nothing in that text asks which side the lawyer would take. The reason is clearest from the winner's side. The party who prevailed has the strongest motive to hire the judge afterward, so a judge who rules for X and soon works for X invites the inference that hope of that work shaped the ruling. A rule limited to adverse representation would leave that inference untouched. It would also leave the losing party watching the person who decided the case join the winner.

Students who have just studied the former-client rule tend to go wrong here. Rule 1.9(a) asks whether the lawyer would take a materially adverse position in the same or a substantially related matter, and the former client supplies consent. Apply that test to Judge Okafor and she looks safe, because Mercer is the party who won. Rule 1.12(a) asks neither question. Its trigger is the same matter plus personal and substantial participation, so the absence of adversity that would defeat a Rule 1.9 problem does not save her. A later section compares the two rules in detail.

The consent exception also differs from the former-client setting in whose consent counts. The text requires informed consent from all parties to the proceeding, confirmed in writing, so the would-be client cannot waive the bar alone.⁸ The party who would face the former neutral across the table has the most at stake, and the text gives that party a vote. The mechanics of consent and the partisan-arbitrator exception in paragraph (d) each receive their own sections below.