[JumpCrisscross]

> That you've replied twice without answering suggests, I think, that there's not an easy answer

There isn't. But we don't need an answer, not yet. The justice system is a lazy evaluator. This case has an easy answer--they are Nazis. If someone sued, the ruling would be quick. If the next case is more complex, reality will illuminate the nuances.

Common law systems are complex. They're also de-centralised and empirical. You don't always need a standard ex ante. We have a cultural standard regarding genocide, its advocacy, and Nazis. Existing norms and laws suffice.

(Philosophically, your question is interesting. It's practically irrelevant, though, until a matching case threatens to arise.)