Is doing an impression of RFK Jr inherently offensive?

[Neo-Malthusian Misanthrope]

I'm a bit of an amateur voice actor, and obviously Presidential candidates are perfect fodder for impersonations. That being said, for those who aren't aware, Independent eccentric/crackpot candidate Robert F Kennedy Jr's distinctly creaky voice is a result of a neurological disorder called spasmodic dysphonia.

Therefore, I've been wondering: is impersonating a particular voice caused by an illness such as this, offensive along the same lines of an impression of somebody with a disability or other impediment, or would it be no different than impersonating Trump's or Biden's rambling? And if not, is it because the condition of his voice isn't in fact comparable to those situations, or are all impressions fair game for public figures for example? I'm not aware of an SNL or similar impression of RFK Jr for reference, and I'm wondering if this line of discussion may be why.

[Xing]

Making fun of RFK Jr. isn't only not offensive, it's our civic duty.

[President Punxsutawney Phil]

Hell No