For anyone unfamiliar with what they’re referencing, it’s more commonly called “Reductio ad Hitlerum” (or more generally, “guilt by association”) and a good summary is given by wikipedia:

Reductio ad Hitlerum (Latin for ‘reduction to Hitler’), also known as the Hitler fallacy or playing the Nazi card,[1][2] is an attempt to invalidate someone else’s argument on the basis that the same idea was promoted or practised by Adolf Hitler or the Nazi Party.[3] Arguments may be termed reductio ad Hitlerum if they are fallacious (e.g., arguing that because Hitler abstained from eating meat or opposed smoking, anyone else who does so is a Nazi).

However it’s important to make note of the most important consideration when applying this rule:

straightforward arguments critiquing specifically fascist components of Nazism like Führerprinzip are not part of the association fallacy.

In this case, exploiting and amplifying distrust in the government (then the weimar republic) was a core aspect of how the Nazi state rose to power, with particular attention needing to be paid to the idea of ‘Dolchstoss im Rücken’ (“stab in the back”), a conspiracy theory about the Weimar government which the Nazis “made […] an integral part of their official history of the 1920s, portraying the Weimar Republic as the work of the “November criminals” who had “stabbed the nation in the back” in order to seize power.” If that sounds suspiciously like the GOP messaging about the idea “the election was stolen” or “democrats are criminals”, well, that’s because there are some extremely relevant parallels between the rise of fascism ~95 years ago and the rise of fascism today.

In terms of either the classic definition, or it’s expansion to the MAGA movement, it’s fairly clear that this fallacy is not applicable to this conversation.