Trump's new tariff can only work as he thinks it will if there's another, partly idle source of similar items, with the spare capacity to seamlessly take over from Chinese suppliers and is one that is guaranteed not to be nuked by a sudden extension of the Tariff.
Does such a source exist?
If not, then, as others have said, this new Tariff is just a tax on American consumers. The importers don't give a toss because they'll just pass the Tariff cost on to the next guy along with the imported items.
 I really hate the term 'consumer'. Have we all really no other use than to mindlessly gobble up everything the producers, advertisers and vendors of 'stuff' want us to?