What the First Amendment really says – 4 basic principles of free speech in the US

Elon Musk has claimed he believes in free speech no matter what. He calls it a bulwark against tyranny in America and promises to reconstruct Twitter, which he now owns, so that its policy on free expression “matches the law.” Yet his grasp of the First Amendment – the law that governs free speech in the U.S. – appears to be quite limited. And he’s not alone.

I am a lawyer and a professor who has taught constitutional concepts to undergraduate students for over 15 years and has written a book for...