If the people are completely brainwashed by lies that are completely contrary to the truth--like nearly a quarter of our population seems to be at the moment--then they will vote for those with the most convincing lies.
If someone who gets their information from Fox "News"--which has been shown to be less reliable than not watching any news at all--is given an equal vote to those who actually know what's going on, Democracy is subverted. At that point you actually have a "fake Democracy", where the country is actually guided by the propagandists and not the people.
The US is one of a very few Democracies with this absolutist attitude about freedom of speech. It's not a required component of Democracy, and it's ultimately self-destructive, but it's clearly (based on the downvotes and responses to my comment) deeply ingrained.
As an example, Trump should have gotten barely any votes in the last election. He accomplished almost nothing besides stacking the supreme court and passing a deeply unpopular tax cut. Yes, we beat him, but 74M people voted for Trump. And those 74M people, nearly 47% of the voting public, were manipulated by blatantly false Russian and Republican propaganda.
To my mind, the "free speech as a religion" POV is looking like it will be the death of our democracy. If we can't fight misinformation, it may bury the country.
And clearly those on HN disagree. I won't argue with you further. But as things stand, we're circling the drain.