Our political order can do a lot to stymie such attempts, but it cannot replace the need for personal virtue. No constitution can save a people from itself.
Cultural grassroots swells of a certain flavor on Twitter and YouTube in particular were quickly handicapped when they started to go viral. I think the cultural/political discrepancy reflects this.
the problem with too liberally being intolerant of "intolerance" is that the definition of "intolerance" is itself a political thing
It can be, but it can also be an attribute of the text. The fact that "Jews should be eradicated" advocates an intolerance of the very existence of Jews isn't a political interpretation because it's right there in the text. The advocacy, the desire to utter the sentiment, is political for sure, but the words that express those politics leave no room for interpretation.
If "too liberally" was meant to communicate this, it's kind of doing a lot of work for its mention in passing.
For example, opposition to more immigration becomes branded as inherently intolerant.
Is this an actual thing? Most of what I see is about a reduction in current immigration, including the deportation of people who have already been here for decades, which is indeed a kind of intolerance for the status quo of border policy. If there's a more charitable interpretation of this state of affairs I'm all ears/eyes.
In fact, when it comes to government regulation of speech, the philosophical approach taken by the First Amendment, and the very thoughtful jurists who have interpreted it, is the opposite: that we must tolerate intolerance.
And as for the social sphere, where legal freedom of speech does not apply of course, the problem with too liberally being intolerant of "intolerance" is that the definition of "intolerance" is itself a political thing, inevitably expanded and wielded as a weapon against dissent. For example, opposition to more immigration becomes branded as inherently intolerant.