John Adams wrote that as a reason why the United States is not a democracy. It's a Constitutional Republic. It's a consistent theme throughout the Federalist Papers.
Individual States and localities have elements of democracy, but the US—built upon knowledge of Rome—is not.
The United States of America is the second iteration of American government, after the one that failed in 1787. The arguments leading up to the 1789 Constitution are quite explicit around why democracies don't work. America is a nation of nations, which is why "these United States" as a plural term was used frequently until after the Civil War, when having it be a singular concept once-and-for-all was of paramount importance.
That said, this is ban is clearly a restriction on freedom of expression, and highly un-American.
Great point about what Adams is actually arguing! Of course, I know the country was founded as/is a Constitutional Republic, but it's always interesting to see how much our modern (American) understanding of democracy differs from how the founders understood it – and also how they shaped the fact that most of us now equate Constitutional Republic with the best form of democracy.
> It's a Constitutional Republic.
Which is a kind of democracy. Democracy is a broad term describing all forms of government where power is granted by the people. This is a weird framing that I see brought up by Americans only, and I don't understand it, because direct democracies (what these Americans are actually referring to when they say 'democracy') are basically extinct in the modern world. They keep trying to distance themselves from the term. Most democratic nations today are presidential or parliamentary republics, just like you, or something that can be approximated to one of them. I'm doubtful that the US founders didn't recognize they were founding a democratic nation, just a specific subcategory - but ultimately still a state that should hopefully answer to the people.
Neither does federalism relate to the form of government - you could have a federal or distributed direct democracy if you wanted to. They're just different categories of things, the way you choose how to best represent the will of a group of people is a different question from how you subdivide these groups into self-governing blocks.