[Natsu]

The "intolerance" Popper talked of preventing was this:

"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 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."

Cite: http://www.goodreads.com/quotes/25998-the-so-called-paradox-...

So his justification for this was founded on a prevention of violence. We already have this in the USA, for example, in that we forbid incitement to violence, fighting words and the like. So unless you can show some strong nexus between these statements and actual, physical violence of some kind, you can't use Karl Popper as a justification.