This is what happened in People v. Abrams, decided by the Colorado Office of the Presiding Disciplinary Judge Feb. 12, but just posted on Westlaw a few days ago. Colorado lawyer Robert E. Abrams referred to a judge as a "gay, fat, fag" in an e-mail to his clients. Eventually, his relationship with the clients became strained (apparently mostly based on other reasons), and after he withdrew from representing them, they filed a complaint with bar authorities, based in part on his speech about the judge. The Colorado Supreme Court ruled against Abrams based on Colorado Rule of Professional Conduct 8.4(g), which says that a lawyer may not

engage in conduct, in the representation of a client, that exhibits or is intended to appeal to or engender bias against a person on account of that person's race, gender, religion, national origin, disability, age, sexual orientation, or socioeconomic status, whether that conduct is directed to other counsel, court personnel, parties, judges, judicial officers, or any persons involved in the legal process.

The court added:

In his private life, Respondent is free to speak in whatever manner he chooses. When representing clients, however, Respondent must put aside the schoolyard code of conduct and adhere to professional standards. Just as our language, norms of social engagement, and the Rules of Professional Conduct evolve, so too must Respondent. This is because lawyers' words and deeds reflect on the values and ideals of today's legal profession. Lawyers are also officers of the court, so their conduct signals to clients the quality of justice and the measure of fairness that can be expected from the legal system as a whole. That system is meant to serve all and dispense justice equally, without regard to race, gender, religion, national origin, disability, age, sexual orientation, or socioeconomic status; when lawyers represent that system, their conduct must give effect to those principles.

A few thoughts:

[1.] Note that the rule isn't limited to slurs, but extends to any conduct or speech. Telling a client that he should try to avoid a particular judge because the judge is old or Catholic or rich would likely be covered as well, as "conduct … that exhibits or is intended to appeal to or engender bias against a person on account of that person's …. religion, … age, … or socioeconomic status."

[2.] On its face, this would apply to statements about any "person," including the President, legislators, and others. The court mentions that the judge was "a participant in the legal process," but nothing in the rule limits "person" that way. And even if the rule were limit to speech about such participants, it would equally apply to speech about police officer witnesses, about government officials one is suing, about government lawyers on the other side, and of course about all the other people, prominent or not, who are involved in the process.

[3.] This is also the rule that the American Bar Association wants to extend (albeit with somewhat different language, cast in terms of "harassment," such as "demeaning verbal … conduct") beyond just "representation of a client": The proposed rule would apply to speech in "bar association, business or social activities in connection with the practice of law."

[4.] Whatever the value of preventing lawyers from insulting witnesses, parties, and the like to their faces, it seems hard to see a sufficient justification for preventing lawyers from insulting judges, witnesses, or others in private communications to their clients, whether the insults are biased or not.

(Abrams was also found to have committed other misconduct, involving excessive fees, but that is beyond the scope of this post.)

UPDATE: I originally erroneously said this was a Colorado Supreme Court decision, given the first line of the second page; but Prof. Robert Fusfeld (University of Denver) corrected me on this—the case was apparently before a special administrative tribunal appointed by the Court—and I in turn corrected the post. My apologies, and many thanks to Prof. Fusfeld.