Joshua Geltzer co-wrote for Just Security on why the First Amendment can constraint President Trump's use of Twitter:
President Donald Trump may be the first resident of the White House to be a prolific user of Twitter, but he probably won’t be the last. Indeed, government officials around the country are already taking to Twitter and other social media platforms to speak to their constituents, hear from them, and facilitate an exchange of ideas with and among those constituents. That makes Trump’s practices on Twitter not merely a temporary curiosity but, instead, a harbinger of politics in the digital age—and a test case for how existing law should apply in this space.
Although politicians’ use of social media can enhance opportunities for important public debate, we believe that one aspect of Trump’s practices runs afoul of the First Amendment. That’s why, today, our Institute for Constitutional Advocacy and Protection at Georgetown University Law Center is filing an amicus brief on behalf of leading First Amendment scholars in support of the Knight First Amendment Institute’s lawsuit against the President for engaging in impermissible viewpoint discrimination by selectively blocking critics from his @realDonaldTrump Twitter feed.