If you need a reminder about why the First Amendment is so important, consider what the world looks like without these kinds of constitutional protections. A man in the Czech Republic faces criminal charges for attending an anti-government rally while wearing a shirt and a backpack festooned with a forbidden symbol: the letter “Z.” Why a “Z,” because the letter is understood as a sign of support for Russia’s brutal assault on Ukraine, and the emblem of the Wagner Group, Russian mercenaries who are leading that criminal enterprise at the behest of Vladimir Putin. That kind of advocacy is morally...