Does President Trump have a First Amendment right to say what he wants on Twitter?

On Tuesday, Twitter used a fact-check label on two of President Trump’s tweets about voting by mail. In response, Trump complained that those fact checks violated his First Amendment rights. Twitter didn’t flag his other tweets promoting a debunked conspiracy theory involving MSNBC host Joe Scarborough. Trump took things a step further today, threatening to regulate Twitter and other social media platforms. That’s something many big tech firms have been trying to avoid.