There are narrowly drawn statutes under which Congress ceded some power over tariffs to the President. I seem to recall the broadest powers ceded were in specified sectoral tariffs (so the steel and aluminum across-the-board tariffs are probably good). The rest of what Trump has been doing is only legal if it is justified by an emergency, and a condition that has existed for decades -- trade deficits with various countries -- hardly constitutes an emergency. Properly tariffs, like any other tax, should be in legislation originating in the House of Representatives, not executive orders. The courts are almost certainly right on this, particularly as the court of original jurisdiction for this is a specialized court which decides on all trade matters.
Permit me to disagree just a little. You are bleeding. It isn't a lot, but it just doesn't stop. When you started bleeding, it wasn't profuse enough to be considered life threatening (i.e., not an emergency). But if you continue bleeding over a period of hours, days, or weeks, if your body can't replace the blood as fast as you are losing it, it will become critical at some point. At that point, it will be an emergency.
Our trade policy has left us bleeding for a long time. It doesn't have to be an obvious arterial spurt to be life threatening over the long haul, but at some point that slow bleed will reach the point where the patient is critical, and it is then, indeed an emergency.
How anemic do we have to get to do something about it?