Also not a lawyer, but I think that there are legislated laws that superseded that, and since its legislated, you can't just go back and choose to enforce one law without the others.
In particular, Wikipedia tells me that the Reciprocal Tariff Act of 1934 had a part makes it harder to go back:
"Another key feature of the RTAA was that if Congress wanted to repeal a tariff reduction, it would take a two-thirds supermajority. That means that the tariff would have to be especially onerous, and the Congress would have to be especially protectionist. Once enacted, tariff reductions tended to stick.
In particular, Wikipedia tells me that the Reciprocal Tariff Act of 1934 had a part makes it harder to go back:
"Another key feature of the RTAA was that if Congress wanted to repeal a tariff reduction, it would take a two-thirds supermajority. That means that the tariff would have to be especially onerous, and the Congress would have to be especially protectionist. Once enacted, tariff reductions tended to stick.
https://en.wikipedia.org/wiki/Reciprocal_Tariff_Act#Reciproc...