If the President (any of them) posted here at HN, and starting saying things against the site and community rules, then I would 100% hope that the moderators would "police his speak".

The President is a person, not a god. If they want to use a private platform to speak, then they have to accept that platform's rules, just like anyone else. If they don't like that platform's policy, then they can use any other platform in the world.