If I may project a little, I think the commenter is pointing to language that’s been cropping up essentially calling big name republicans traitors for endorsing Kamala. While you’re more than allowed to interpret what they said literally, I read it has intentionally a bit hyperbolic to make the point that a huge portion of the Republican Party will literally blindly follow him, even if the party leaders are starting to flake.

Just remember, rewording this statement:

If big name Republicans aren’t going to vote for him, why are you assuming all other Republicans will?

To the version that would exemplify your interpretation:

If big name Republicans are going to vote for him, why are you assuming all other Republicans will?

Still creates an equally bold, and hyperbolic claim. Sometimes people use words like “all” and don’t really mean every last person. I blame the English language, not the people taking words literally, for misunderstandings like this.

Just remember, especially with politics, people often hype up language a bit, it makes statements carry more oomph, and can help keep supporters excited for whatever movement they are supporting.