The argument of the commenter you're replying to is not that "Shapiro is (or could be) far-right because [...]". Rather, the argument is "The argument that a Jewish person cannot be far-right is invalid because [...]". The difference is subtle, and of course the person you're answering may well consider Shapiro as being far-right, or even a literal fascist. And you both may disagree on the strict definitions of both terms but, either way, accurately representing other people's arguments is a key point of intellectually honest debate and assuming the best intentions. Case in point:

1. The article mentions Shapiro as being "right-wing".

2. Top-level comment first implies the article says Shapiro is "far-right", and then confounds the general concept of "far-right" with maybe Nazism or antisemitism in general to make their argument that him being Jewish makes it impossible that he is far-right.

3. A reply states that Jewish political figure Stephen Miller identified with white supremacy and fits the(ir) definition of a fascist, as a counterpoint to the previous argument.

4. You disagree with the argument that Shapiro is (or could be) far-right, because you disagree that Stephen Miller fits the strict definition of Fascism.

...and all this was originally triggered because the linked article said:

«Most days, the “top performing” links come from right-wing commentators and provocateurs like Dan Bongino, Ben Shapiro, Fox News and others.»