Ad hom isn’t intended to specifically thought-terminate people. It’s just a thing you sling at people.

The use of “tankie” or “terrorist” is to define [person speaking or being spoken about] as a “baddy person” and therefore absolutely anything and everything they say can and should be disregarded, otherwise you are also a baddy person and thus not a good person. It’s intended to reinforce group-think. The reactionary right use “woke” with the intent of preventing their members from listening to something a “woke” person might say, to make sure that they thought-terminate and do not think about whatever is said. The purpose is to function as a shield against anything that might change their views. It’s to shut down their brains to anything people might say to them.

It has the appearance of ad hom, but it has a specific higher function.