The transgender activists are more in line with the spirit of Popper's message. Popper, as a Jew, was primarily concerned with opposing fascism, the greatest challenge to Jewish power. Fascists are enthusiastic supporters of debate, because they are confident that their ideas will reign supreme.

Popper inserts a convenient loophole:

In this formulation, I do not imply, for instance, that we should always suppress the utterance of intolerant philosophies; as long as we can counter them by rational argument and keep them in check by public opinion, suppression would certainly be most unwise... We should therefore claim, in the name of tolerance, the right not to tolerate the intolerant. We should claim that any movement preaching intolerance places itself outside the law, and we should consider incitement to intolerance and persecution as criminal, in the same way as we should consider incitement to murder, or to kidnapping, or to the revival of the slave trade, as criminal.

Liberal ideologues such as Popper must rely on violence to preserve their worldview, because liberalism is incoherent and its flaws are readily exposed. Gender ideology is not up for debate for the same reason that multiculturalism and the Holocaust mythos are not up for debate -- it is because our opponents have no argument.