The thing is, they have no real reason to care about the threat of a tariff. It makes domestic US prices increase. For a lot of things, there isn't the ability to start making it domestically in a timely fashion, so either demand drops for a bit or if it's something vital, then the producer never even notices.
It's threatening the shoe store by waving a chainsaw at your legs. Sure they'll have some reduced sales, but you're mostly hurting yourself.