Or HaChaim on Exodus 23:2/אור החיים על שמות כ״ג:ב׳

1 לא תהיה אחרי רבים לרעות, "Do not follow a multitude to do evil;" Our sages have offered a multitude of explanations on this verse none of which appear to address the plain meaning of the verse. I believe we need to understand this verse in terms of Numbers 35,24 and 25 ושפטו העדה…והצילו העדה. Our sages (Sanhedrin 4) comment there that when the court is to decide in matters which carry the death penalty there have to be a minimum of 23 judges in order that there could be a quorum (10) which indicts and a quorum which (may) exonerate. The extra number is designed to enable a majority to be present at all times. On folio 17 of the same tractate we are told that should all the judges indict unanimously the accused goes free.

2Our verse intends to remove two obstacles which may mislead a scholar when he ponders the meaning of this ruling. 1) When a judge sits in a collegium of judges and he notices that all his colleagues have made up their minds that the accused is guilty, whereas he feels that the accused is innocent, he may say to himself that by voting according to his conscience the accused will be executed seeing there are already two quorums, one which votes "guilty" and one which could vote "innocent;" this judge may say to himself that if he too votes "guilty" the accused would be freed seeing the guilty vote would be unanimous, the result he has been arguing for. He will justify his behaviour by recalling the dictum of the sages that when faced by a majority one must not insist on one's own opinion. The Torah instructs such a judge not to apply this dictum when voting to indict someone. One must only vote one's own conscience even if the result of such a vote does not correspond to one's wishes or convictions. The Torah uses the word לרעות advisedly, telling such a judge he would do something evil by voting with the majority in order to thwart their purpose. Such a judge is to remember that in the final analysis G'd is the judge; if G'd instructed the judges to let the accused go free in the event they agree unanimously that he is guilty, this does not give the dissenting judge the right to play G'd, i.e. to be the final arbiter of the fate of the accused.

3There is still a second obstacle that a judge may face in such situations. Assume that the judge in question is convinced of the guilt of the accused. He is aware that his opinion is shared by all his colleagues. The judge in question realises that if he votes his conscience, i.e. "guilty," this will make the vote unanimous and result in the accused (whom he thinks of as guilty) going free. In order to prevent this from happening our judge resolves to vote "innocent" in order to ensure that the accused will be convicted. By doing so our judge convinces himself that he merely ensures that the majority will prevail, a laudatory objective. However, morally speaking, this too is a way in which a single judge imposes the outcome of a trial on the majority. To prevent this from happening the Torah wrote לא תענה על ריב לנטות אחרי רבים, "neither shall you vote in a dispute so as to ensure the vote will be based on a majority (as opposed to unanimity)." The Torah explained the reason for this legislation as being להטות, i.e. that the individual judge in question attempts to pervert the outcome of the proceedings by not voting his conscience.