https://www.cnbc.com/2018/01/05/twitter-world-leader-tweet-ban-policy.html

Twitter doesn't want to get in the way of elected officials and political leaders communicating via the platform — no matter how "controversial" their tweets may be.

"Blocking a world leader from Twitter or removing their controversial Tweets, would hide important information people should be able to see and debate," the company wrote in a blog post. "It would also not silence that leader, but it would certainly hamper necessary discussion around their words and actions."