This would only work assuming such a group could gain enough power to overthrow local PD and eventually the US military, etc., which is kind of unrealistic for an group that is not supported by a majority of the population.
The wikipedia page on this notes people dispute this idea, sourcing John Rawls as a notable example.
Not really. A little further is this -
"However, Rawls also insists, like Popper, that society has a reasonable right of self-preservation that supersedes the principle of tolerance: "While an intolerant sect does not itself have title to complain of intolerance, its freedom should be restricted only when the tolerant sincerely and with reason believe that their own security and that of the institutions of liberty are in danger."[2][3]"
I looked and Rawls explicitly says he disagrees with it.
What you have quoted here is saying physical safety is sincerely in danger. To me this is like him saying it's ok to eliminate terrorist groups, if that is what they truly are.
The wikipedia page on this notes people dispute this idea, sourcing John Rawls as a notable example.