Political data guru Nate Silver of FiveThirtyEight.com recently tweeted that Mark Zuckerberg’s comments about free speech were mistaken because “false statements of fact aren’t protected speech in the U.S.” That was a false statement—which, fortunately for Mr. Silver the First Amendment does protect. As the saying goes, the remedy for bad speech is more speech.

Those who want to purge “misinformation” from social media should learn from this incident. Mr. Silver is smart, thoughtful and well-educated. He’s an active participant in policy debates and has every reason to be familiar with the First Amendment. And the First Amendment isn’t an obscure area of law. Most Americans are broadly aware of it; it is constantly discussed and in the news and throughout the education system; it is foundational to our democracy. How can someone like Mr. Silver confidently misstate such a familiar part of U.S. law?

More to the point, if someone whose full-time job is to analyze politics and policy can get the First Amendment wrong, how can anyone be expected to understand more-complex policy issues—housing, banking, health care, technology, trade, national security?