This isn't the ACLU's fault. Their job is to defend the first amendment.
No it's not. They don't have to jump in to defend them (especially since it runs at direct counter-purposes to their efforts such as defending the civil rights of black, LGBT, Muslim Americans etc by empowering them and giving them more power to spread their hate and intimidate others, making more work for themselves and more messes they have to clean up in the future). They could have let someone else do so and stand up for these particular people's rights--it doesn't have to be them. But they chose to. Nothing forced them to. They decided to of their own free will. That's their choice. But it being their choice, they don't get to suddenly turn around and act like they had no part in these events occurring. Don't get to have it both ways, that they'll defend them and let them hold these events and they'll do everything in their power to make sure that they're able to be held, but suddenly they have nothing to do with it if things go south, as if this was all some unknown risk with these type of things that no one could have possibly seen coming. If they're going to defend that speech and they're rights to have it, own the consequences of doing so. Don't half-ass it.
To be perfectly, 100% clear, of course the people at fault are the white nationalist fucks doing this stuff in the first place. That ain't in question. But if the ACLU are going to defend their right to speech and to organize, and to help make sure these evens happen when others are trying to stop them, they have to own the consequences when things go south. Don't get to make sure an event happens, but then act like things going south if they do has nothing to do with you when you played a role in making sure that event happened to begin with.
To be clear, they are not the primary culprits. Those are the white nationalists and neo-nazis in attendance and the driver of the car. But nonetheless, they played a role in making sure this event happened. They don't get to back away from the consequences of such events, just because it's inconvenient for them. It's not primarily their fault. But they played a role, and should be held accountable for that particular role and not let off the hook.
You choose to defend their speech and their right to organize and the like? That's a personal choice. But if you make that choice, you have to be prepared to shoulder part of the burden for that decision if things go south as a direct result of that choice. After all, no one forced them into it. That's one they made. They're not burdened to do so. They chose. And they need to bare the weight of that choice. No half-assing it saying they'll defend the rights of these individuals to organize and speak to the death, but if something goes wrong at one of the events they made sure, suddenly they had nothing at all to do with the event they helped to make sure happened in the first place. Doesn't work that way. Own that shit. Of course the white nationalists are the ones primarily responsible, but they too had a role since they chose to do everything they could to make sure stuff like this happens and if stuff like this happens at events they made sure happened, that gives them a role in it whether they like it or not.
The ACLU doesn't like it? They can let someone else defend the rights of white nationalists and neo-nazis to "peacefully organize" and spread their hate or whatever. Till then, they don't get to have it both ways.