I suspect this is a false charge, although there’s not enough information to be sure.
Naturally a father should come to the defense of his son if he is being bullied in school, and has every right to complain to the principal or the schoolboard if he feels that an injustice has been done.
Nothing in the article suggests that he used his official position as a judge. If the principal refused to maintain discipline and if he then spoke to influential friends about it, it’s still not clear to me that he is abusing his position as a judge. Normally that just means that a judge must recuse himself from a case if he has a personal stake in it. That doesn’t appear to be the allegation.
As you say, his crime is probably that he is a conservative in a highly liberal state.
Of course there is “[n]othing in the article [to] suggest that he used his official position as a judge”. The article doesn’t describe what his alleged improper actions were. The article is about Rivera-Soto’s legal response to the charges brought against him by the Advisory Committee on Judicial Conduct (do you expect the judge to provide the newspaper with a description of his own sleazy behavior; you know, get them material describing what a sleazeball he is?). The article lists the charges; it does not provide description of what precipitated the charges.
Look, you’re free to come to any conclusion you want, but if you’re going to conclude that the judge is the victim of a left-wing smear campaign based on this article, please call me. I’ve got a bridge in Brooklyn to sell you.