There are limits to the attitude of reasonableness’.
You cannot have a rational discussion with a man who prefers shooting you to being convinced by you.... It is the same with tolerance. You must not, without qualification, accept the principle of tolerating all those who are intolerant; if you do, you will destroy not only yourself, but also the attitude of tolerance.
Unlimited tolerance must lead to the disappearance of tolerance. If we extend unlimited tolerance even to those who are intolerant, if we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them.
As long as we can counter them by rational argument and keep them in check by public opinion, suppression would certainly be most unwise. But we should claim the right to suppress them if necessary even by force; for it may easily turn out that they are not prepared to meet us on the level of rational argument, but begin by denouncing all argument; they may forbid their followers to listen to rational argument, because it is deceptive, and teach them to answer arguments by the use of their fists or pistols. 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.
Some people think that there is a contradiction in this—if not in the idea of the tolerant refusing to tolerate the intolerant, then at least in the idea that they may suppress some instances of intolerance while being willing to tolerate others. But the paradox of tolerance is not that the tolerant are being intolerant when they refuse to tolerate intolerance. It is that they may, by being too tolerant, unwittingly promote intolerance in others—and with it their own demise.
This, enables us to see what is really at stake when it comes to tolerance. The intolerant would forcibly restrict our freedom because of who we are, or because of what we believe and say. And there is no point appealing to reason or talking about contradictions when it comes to this. We must claim the right to forcibly oppose their intolerance if we are to keep any rights at all.
Your picture of those holding a poster regarding fascists, doesn't upset me one bit. The last thing I want to see in this country is a fascist takeover, and neither does Antifa. That's why they are confronting fascists and White Supremacists everywhere. Fascist intolerance will not be tolerated.