http://www.washingtonpost.com/blogs/the-switch/wp/2018/05/23/trump-cannot-block-twitter-users-for-their-political-views-court-rules/

President Trump's decision to block his Twitter followers for their political views is a violation of the First Amendment, a federal judge ruled Wednesday, saying that Trump's effort to silence his critics is not permissible under the U.S. Constitution because the digital space in which he engages with constituents is a public forum.

The ruling rejects administration arguments that the First Amendment does not apply to Trump in this case because he was acting as a private individual. In a 75-page decision, Judge Naomi Buchwald said Trump, as a federal official, is not exempt from constitutional obligations to guard against "viewpoint discrimination."