Speech such as the Holocaust didn't exist doesn't represent immediate harm, and as despicable as it may be, is protected.
I think what you see as a huge gulf, I see as a moderate width river.
If anything, I might now argue this is case can be considered an example of “fighting words”, a concept which varies between legal jurisdictions but certainly does exist in the USA.
On further consideration, given the trigger phrase the dog was trained on, it might (IANAL) be argued to be “incitement”, which is also a thing which exists in USA law.
That's exactly it, this is clearly not incitement according to US law. Here are the two important concepts:
https://en.wikipedia.org/wiki/Clear_and_present_danger https://en.wikipedia.org/wiki/Imminent_lawless_action
According to the latter, the smell test is:
> "Advocacy of force or criminal activity does not receive First Amendment protections if (1) the advocacy is directed to inciting or producing imminent lawless action, and (2) is likely to incite or produce such action"
The pug case in no way comes close to either of those clauses. I'd argue, from a legal standpoint, this is absolutely simply teaching his dog to salute. It's crass, rude, and offensive but also perfectly legal under any meaningful definition of free speech.