Freedom of speech is--at its heart--the ability to openly criticize government and those who govern without fear of prosecution. The US doesn't rate super high on various metrics for individual freedoms, despite what we would like to believe, but we do consistently rate among the highest (if not the highest) for freedom of speech and for support of that freedom. With that in mind, there are still content-specific and contextual restrictions on speech in the US and other places which rate highly for freedom of speech. The simplest example is for threats and calls for violence. Obviously, it is unwise to allow something like a march at a political rally to carry on a chant calling for extrajudicial killings of their political opponents because that's advocating for and potentially inciting a violent crime.
The tricky part is identifying when promotion of certain ideologies becomes equatable with inciting crime. We have some examples of this on the books, the obvious one being Nazis, but even Neo-Nazis in the US are permitted to organize and promote their ideology publicly. This is despite the fact that Neo-Nazism is built almost entirely on social and cultural values of the original Nazis and not their governing, economic, or even diplomatic values. The most prevalent of these social values are white supremacy, eugenics, and antisemitism, and even their strong trends towards nationalism are inseparable from the issue of ethnicity, making ethnonationalism a better descriptor. These social and cultural values call for suppression and removal of non-conforming peoples, and historically this has been done through displacement and genocide. The fact that this ethos openly calls for racial and religious discrimination and its followers have shown a willingness to violently persecute others could qualify it as incitement, but currently it does not. As soon as one of them slips and says "kill the Jews" then they're open to prosecution, but "guilt by association" is a no-go here even when the associate in question is literally Hitler.
So, at what point can we say some political or ideological group has gone beyond the pale of protected political speech/protest and into the realm of calling for violence or incitement of some crime? Legally, should we draw a line at all, or is that just codifying a means to persecute technically innocent people on the basis of association? Can we risk the potential for even more institutional bias/favoritism?
That is all assuming, of course, that there is genuine discourse being had. Actual people promoting their personal ideologies, for better or worse. When you venture into the realm of fake news (and I mean actual fake news, i.e. disinformation, conspiracies, etc.) then the ethicality becomes simpler but the legality becomes somehow more frustrating in the US. As I mentioned before, we can probably all agree that any media outlet which brands itself as "news" but whose content is entirely politically-motivated commentary and knowingly lies or omits facts and context--to the point that they cannot be said to offer any form of fact-based reporting--shouldn't be trusted. However, knowing that you shouldn't trust what they say is irrelevant to their right to say it in the first place. The FCC has very narrow scope on what they will and won't enforce with regards to the truth of statements in news media. Technically it is legal to lie, even when "reporting" as a "news" outlet, so long as those lies do not cause immediate public harm. The FCC will come down on a network which broadcasts that it's safe to drive through an active forest fire if that specific forest fire is referenced and is active at the time of the broadcast. If it's a month after the fact and the talking heads open with "recent studies have shown..." then the FCC is powerless to punish them for it even if there are no studies and there are active forest fires elsewhere at the time of broadcast.
How this relates to our ideological concern is that it's tolerated for these networks to broadcast the opinions of those who follow what many would consider to be dangerous ideologies rooted in racism, sexism, and religious discrimination (almost always including antisemitism, but islamophobia is prevalent now as well). They are even allowed to be openly discriminatory on air, as seen in segments on the "Great Replacement" conspiracy theory, as long as they do not attempt to incite an immediate, violent panic. Even then, the network can run a disclaimer saying the opinions expressed by those on the show are their own and not those of the network, so only the person who actually spoke is liable.
You may see some comments saying more and more extremists are "saying the quiet part out loud," which simply means that the proponents of these ideologies which we already knew were dangerous are finally starting to feel comfortable saying the dangerous parts in public spaces. Using Neo-Nazis as an example again, we've had organized Neo-Nazi parties in the US for over half of a century, and historically their public talking points have been anti-desegregation, anti-civil rights, anti-LGBT rights, etc. etc., which are all literally conservative positions (i.e. deference to status quo, and opposition to change) and were stances taken by mainstream political parties at the time. They are also noteworthy for opposing suggested changes and for not recommending alternatives to the status quo. It is known that the status quo in the US in this time frame was not aligned with the social and cultural values of Neo-Nazis, but the Neo-Nazis knew it would even further discredit them if they openly promoted discriminatory policies such as expansion of segregation to Jewish people. It is common knowledge that antisemitism is a core value of Neo-Nazism, but they knew better than to push it in public. Now, however, promotion of these less popular aspects of Neo-Nazism and other ideologies is becoming tolerated in public and private spaces, though it is often presented obliquely. That's my tie-in to this:
I didn't mention Jews in every sentence because at this point in time, virtually all major conspiracy theories have some roots in antisemitism. Many prevalent conspiracy theories in western countries will include mentions of George Soros, the Rothschilds, other international banking institutions like the IMF, "Zionists," Israel, or the "global elite" which is a blanket term for all of the above. You cannot escape antisemitism in contemporary conspiracy theories. Whenever some talking head on political-right media mentions any of the above, they are pushing antisemitism whether they are consciously aware of it or not. If directly pressed on the matter, they will probably backpedal and go with the usual "I'm not antisemitic, some of my friends are Jewish" nonsense, but it doesn't change the fact that they are demonizing Jewish people by associating them with totally unrelated scandals and fabricated conspiracies.