In papers filed Friday, lawyers for President Trump sought summary judgment in a First Amendment challenge to the President’s blocking of users on Twitter (see our prior coverage here). The brief argues (among other things) that President Trump’s use of Twitter does not constitute “state action”:

"Here, the President does not operate his personal Twitter account by virtue of federal law, nor is blocking made possible because the President is clothed in Article II powers. His use of the @realDonaldTrump Twitter account is not a right conferred by the presidency. Twitter is a private platform, run by a private company, and it structures the interactions of its users on its own terms. The President established the @realDonaldTrump account in 2009, has used the account before and after his inauguration, and will be free to use it after he leaves office. Throughout, his use of the account has been governed by Twitter’s own structural limitations; any features he may or may not use are created by Twitter and shared by every other user. The blocking feature, for example, is one several tools Twitter provides to allow users to customize their interaction with other users and to curate the information that they consume. And the President’s decisions about who to interact with and what information to consume (what newspapers to pick up, what news programs to watch, what accounts to follow or block) are not state action.

To be sure, the President’s account identifies his office, and his tweets make official statements about the policies of his administration. But the fact that the President may announce the “actions of the state” through his Twitter account does not mean that all actions related to that account are attributable to the state. Public officials may make statements about public policy—and even announce a new policy initiative—in a variety of settings, such as on the campaign trail or in a meeting with leaders of a political party. The fact that an official chooses to make such an announcement in an unofficial setting does not retroactively convert into state action the decision about which members of the public to allow into the event. Similarly, the President’s decision to block Twitter users on his personal account is not properly considered state action. "