> Much of Europe concluded that, although free speech is important, views that threaten democracy itself are different and can be criminalized; see laws in various European states against Nazi propaganda.

It should be noted that being the one to define what "democracy itself" means comes with great advantages. It has little to do with what the people want (what one might naively think "democracy" means) - no no, that is "populism". "Protect democracy", rarely (if ever) means free elections, free speech, or the right to oppose government. What it means is more censorship.

> Europeans might retort that the American system, too, has failed to stop threats to freedom of expression.

As a European, it brings me no comfort that free speech is in peril even in the US.