Subject: Re: Trump corners SCOTUS
Do you know if there is any legislative history which might shed some light on what Congress intended?

Oh, yes - there's a ton of legislative history. It was extensively discussed in briefings and the oral arguments. This was a whole thing back in the day, when Richard Nixon used the predecessor statute - the Trading With the Enemy Act (TWEA) - to similarly impose tariffs under a claim of national emergency (but really because we were having balance of payments problems). That was hugely controversial, and Congress went back and completely rewrote the TWEA in response to Nixon's actions in order to curtail the scope of powers that Presidents could assert in emergency situations.

https://en.wikipedia.org/wiki/...
https://en.wikipedia.org/wiki/...

So there was a lot of debate, both in the lower courts and in the SCOTUS proceedings, over whether the cabining of Presidential authority that Congress engaged in when replacing TWEA with IEEPA had the effect of restricting the scope of the "regulate" power, which Nixon had asserted.