Trump's twitter account has been determined to be a public forum by Federal Judge Naomi Reice Buchwald - read the NYT's report here. 

Trump has the right to "mute" a user (so only Trump cannot see the content Trump finds objectionable) but Trump violates the constitutionally proctected free speech of citizens if Trump "blocks" other twitter users who make comments to which Trump objects.

The Detroit Shoreway CDC is in violation of Federal Judge Naomi Reice Buchwald.   Maybe a cease and desist letter is in order.