All the way up to the SCOTUS, at which point it'll be a 7-2 vote in Trump's favor.
There were a bunch of sentences regarding non delegation of powers of congress, mainly for federal agencies, and courts deciding that congress can't delegate those faculties, so, by the book, this would be a similar situation. There is actually an ongoing case for this aspect of the discussion:
https://www.theguardian.com/us-news/2025/apr/07/trump-tariff...