All of this. When the reality is that a political movement will operate in bad faith and intentionally, aggressively exploit any such ideological fulcrum as a weakness in a coordinated way, clinging to deontology makes you a knowing ally… which means you have taken sides.

I can see why this discussion's turned ugly, but it can't NOT be ugly. None of this is hypothetical. It's blown up because the aforementioned Nazis worked out that they could compel the ACLU to effectively become a Nazi ally and devote their forces to the cause of terrorism. Under the ground rules of what the ACLU is, if properly managed, the organization can be used to clear the way for violence and actions that are not on brand for the ACLU, and not what it thinks of as 'civil liberty'.

This is a clever sort of meta-gaming thing, but it's also an obvious existential crisis for the ACLU to the extent that the ACLU cares at all about terrorism. I think there's an assumption that we can define some things with a bright line never to be infringed upon, and that there will never be exploits to undermine our assumptions.

And I mean, that's not even true for mathematical proof, much less free-speech liberalism.