An uncensored media feed for any politician with any power at all is just going to be an uninterrupted stream of vitriol.
The politician should mirror the post on a website the politician controls with no comments allowed or simply post on such a website in the first place. The politician can then post a link to the relevant page of the politician's website to the politician's social media accounts and proceed to ignore the comments on the social media site. If the politician is a government official, this is still perfectly compatible with the First Amendment, because the official has the First Amendment freedom of association and therefore can refuse to host comments on the politician's announcements on the politician's own websites.
"People I like."
> trolls
"People I don't like."
Either of whom may or may not be constituents. In fact the people most motivated to 'troll' (give voice to dissent) will be the people who have a stake in the matter; constituents.
You could have a handful of people convinced that some politician is a satanic pedophile and will write hundreds of comments about it, while someone who just would like the pothole in their street fixed, or who disagrees with their vote on a zoning issue never gets a word in.
Go on a forum with lots of republicans and argue standard democratic talking points; they'll call you a troll. Do the inverse and they'll call you a troll. People use the label of "troll" against people who are being earnest when they say something the listener strongly disagrees with. It's little more than a generic insult for people you disagree with, like "idiot".
In the example you give, the people calling politicians satanic probably earnestly believe that in many if not most cases. You might think that nobody could have that point of view in good faith, but this is a country with many millions of Christians who earnestly believe all kinds of wacky nonsense. I know Christians who think Halloween is a satanic holiday. They're not trolling, they really do believe that. You say that people who accuse politicians of satanism are trolls because you strongly disagree with what they're saying and you think they don't have a rational reason to believe what they say (which is probably true) but you don't have any evidence that they're misrepresenting their true beliefs to get a rise out of you (which would be "true trolling".) If they really do believe what they say, then they're not trolls. Even if what they believe is totally irrational, that's the way some people are.
If the problem is a small number of people dominating the conversation by leaving 100x more comments than anybody else, then solve that problem by requiring commenters to identify themselves and rate limiting people. This doesn't require you to read their minds to determine their true intent.
That might be the constitutionally mandated outcome, but it's probably preferable to just not allow comments at all.