You'd think that with all the fuss over trolls and hate mail in blog comments that somebody would have come up with the obvious solution.
Instead of censorship or turning off comments, simply have a second set of comments. Nobody can post to them: they are the deprecated, shameful, unwanted, proscribed, improper, hateful, obscene, or otherwise inappropriate comments. Blog editors can consign noisome comments there (or back) with a simple checkbox. Perhaps checking an explanation category too. Perhaps some posters' comments are automatically put there. Readers can see exactly what is and isn't thought appropriate.
This accomplishes too things. It allows blog editors to maintain the atmosphere they want with the same effort it takes to delete a post. And it produces editorial transparency: communication of disapproval without censorship.
Doubtless some won't want this system. In my 30+ year experience of mail lists and news groups (starting on the PLATO system), trolls actually benefit many groups because they lead people to face their own understanding of the topics with more than just belief. But when there is a high volume of obnoxious or off topic posts, this might be a good solution.