Earlier quoted context omitted.
This is the paradox of tolerance. A truly tolerant society would tolerate intolerance, which makes the society not truly tolerant anymore. So a society would need to be a bit intolerant to stamp out intolerance, making it overall more tolerant.
Forget tolerance I want liberty back. What makes tolerance so good that it should be prioritized over everything else? I want everyone granted certain inalienable rights and then allowed to live how they want as long as they abide by their rights and the rights of others. If people want to use their right to vote, follow the process, and support something that others disagree with, that's liberty in action.
In other words, you want to prioritize tolerance over liberty.
Not even the most hardcore anarchist wants to live in a society where someone else's right to swing their fist doesn't end where their own nose begins, which is what true liberty entails, although they will vocally denounce any form of tolerance even as they implicitly accept it for themselves.
And it's worth pointing out that you don't even actually disagree with the paradox of tolerance in this regard, since the inflection point of tolerance/intolerance Popper claims should be a party refusing to recognize the rights of others or to act within legal bounds - the paradox of tolerance was written as a response to the result of German "tolerance" for Nazism at the time.
No one is actually arguing that mere civil political disagreement shouldn't be tolerated, but rather there is a recognition borne out of history that authoritarian beliefs, if not pushed against, will overwhelm the body politic in a similar way as cancer. Accepting the paradox of tolerance means recognizing that some prejudices and systems of belief are inherently harmful and that their adherents will never simply accept peaceful coexistence with others within the framework of a just and civil society.
Nazis will never play nice, and casting them as a victimized and oppressed group with legitimate grievances with whom we should empathize, and whose arguments we should consider (or reconsider, since nothing the far right has to say is actually new,) will not end well for anyone.
And to serve the forum's inevitable reflex towards whataboutism, this is not to let extreme leftism off the hook. There just happens not to be a surge in hard left ideology happening around the world at the moment, so mentioning the left in the context of this specific conversation for the sake of "balance" wouldn't be relevant.