Everyone loves ad hominem, it’s fucking fun to use. Doesn’t make it a valid argument.
Define validity. Topics like journalism fundamentally depend on trust, so attacking sources is 100% valid. The only source for many claims is going to be dubious and there will often be no other context to invoke because it’s just what some prick in a think tank pulled out of their ass. The only option is to point at the source as being ridiculous and untrustworthy.
These argument approaches sometimes work, for sure. But if the public consensus is anything to go by, there’s limited fucking reach for them.
It definitely works better than sticking to some decontextualized platonic ideal of what arguments follow, which is my overly detailed guess at the alternative you’re thinking of. The problem with ad hominem is that it’s an entry under “fallacies” in Wikipedia, yes?
Sure they’ll work socially, but no institution is going to amplify those messages,
This is a problem for anything outside of the current ruling class’s status quo, though it’s not a 100% effective filter. The system will try to co-opt or villify grassroots narratives and can end up amplifying messages that way, with varying levels of success at deranging the ideas in question.
and it fails whenever you encounter someone who knows to be rightly skeptical of ad hominem arguments.
I’ve never seen it fail. Even the people who think they care about ad hominem use it constantly because authority is (1) a necessary aspect of non-deductive logic and (2) just plain part of how we rationalize our current positions. That person will discount something if Trump says it if they think Trump is a joke. That person will discount anything said by AOC if they think she’s an agent of Satan. That person will discount something said by a scientist that believes the earth is round - because they’re a flat-earther and such a person must be part of a cabal.
It’s easy to deal with: you just start asking them how they know anything about the topic that doesn’t come from an untrustworthy source and whether they just believe claims from charlatans by default or increase their standard of evidence for incompetents and liars.