Last year, several twitter critics of the sitting President sued Trump for blocking them and won. U.S. District judge Naomi Reice Buchwald, of the Southern district of New York, ruled that Trump had violated the plaintiffs' first amendment rights by excluding them from voicing their opinion on a 'public forum.'
We hold that portions of the @realDonaldTrump account—the 'interactive space' where Twitter users may directly engage with the content of the President’s tweets—are properly analyzed under the 'public forum' doctrines set forth by the Supreme Court, that such space is a designated public forum, and that the blocking of the plaintiffs based on their political speech constitutes viewpoint discrimination that violates the First Amendment.
This ruling should have wider implications than preventing Trump from blocking prominent twitter critics like Dr. Eugene Gu, who filed the lawsuit. Besides, Trump isn't the only politician that uses twitter to communicate with his constituents. Almost every representative, senator, justice and bureaucrat uses twitter to get their message out. In this sense, the 'private' social media platform could be considered a designated public forum for political discourse, and therefore should be open to all viewpoints. Unfortunately, there is no legal definition for online public forums. The Supreme Court outlined 3 types of public forums in the 1983 case of Perry Education Association v. Perry Local Educators' Association and all of them are defined in terms of physical space and restrict government officials from discriminating against certain viewpoints rather than public corporations like Twitter and Facebook. This could be a major problem when it comes to twitter itself banning or suspending certain users for unpopular political opinions or selectively enforcing their nebulous terms of service. Twitter's discriminatory actions keep people form engaging with their elected representatives all the same as being directly blocked by their elected representatives; the only difference is that the censorship is done by a corporation rather than a government agency or official. However, as I pointed out in a previous post, corporations are established by governments for the benefit of the public, and have no right to discriminate on the basis of race, sex, national origin, religion or any other protected class. It's only logical to add political affiliation and viewpoint, especially given the pertinence of twitter and other big social media platforms in our day and age.