I haven't had a chance to read the full ruling, but it seems fairly obvious that if a government official designates a particular two-way communications channel as a place for communicating official statements (the Trump administration claims his Twitter account is such a channel), then the government official is subject to some restrictions on how that channel can be policed.
There was a case last year[1] where a federal judge in Virginia made a similar ruling after a politician banned someone from commenting on an official Facebook page due to not liking the opinions the commenter expressed.
And the general principle seems to be that the First Amendment does not allow government officials to silence their critics on an official communications channel; they can choose which channels to use, and refuse to open certain others, but once they set up such a communications channel they cannot discriminate based on the content or viewpoint of critics' speech in such channel. To do so implicates not just freedom of speech, but also the First Amendment right to petition the government for redress of grievances (i.e., if the government official bans you from the communication channels you'd use to state your grievances, how can you exercise that right?).
Congress shall make no law respecting an establishment of religion, or prohibition the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people to assemble, petition the government for redress of grievances.
> it seems fairly obvious that if a government official designates a particular two-way communications channel
I would not be opposed to such a law. One way or another, the first amendment is clearly not that law.
So your approach to First Amendment issues is to disregard the history of judicial interpretation and application in favor of "this case didn't involve a law passed by Congress explicitly doing one of these things, so it doesn't apply".
There was a case last year[1] where a federal judge in Virginia made a similar ruling after a politician banned someone from commenting on an official Facebook page due to not liking the opinions the commenter expressed.
And the general principle seems to be that the First Amendment does not allow government officials to silence their critics on an official communications channel; they can choose which channels to use, and refuse to open certain others, but once they set up such a communications channel they cannot discriminate based on the content or viewpoint of critics' speech in such channel. To do so implicates not just freedom of speech, but also the First Amendment right to petition the government for redress of grievances (i.e., if the government official bans you from the communication channels you'd use to state your grievances, how can you exercise that right?).
[1] https://arstechnica.com/tech-policy/2017/07/politician-dinge...