The same is true for NAFTA. I have friends who worked in the Canadian government department that did a lot of that work and it involved years of work writing detailed regulations in different industry sectors. It will take years to unravel them. And my understanding is that unraveling regulations is not a trivial procedure in the USA . A public body enacted those rules and had to justify why they were doing so. Any public body that undoes them has to do the same.
That's correct: U.S. federal regulations generally need to be established or modified in accordance with a statute,
the Administrative Procedure Act. Regulations typically fill in gaps in the more general language of laws enacted by Congress, and the APA is intended to provide assurance that agency regulations are consistent with their underlying statutes, that there is a rational basis for the regulations, and that the public has an opportunity to comment before the regulations go into effect. The APA also provides for judicial review of regulations promulgated by federal agencies in many instances.
Withdrawal or modification of NAFTA may be even more complicated because Congress enacted a specific statute to implement the agreement. It's not clear whether Trump can simply give notice of U.S. withdrawal, pursuant to Article 2205 of NAFTA, or whether he would need to seek Congressional authority to do so. (Obviously, any modification of the agreement would require the consent of Canada and Mexico.)
It didn't appear that Trump was familiar with either the rulemaking process or the legal status of NAFTA during his campaign for president. He didn't even seem conversant with the president's basic constitutional authorities, for that matter. He gave the impression he believed he could change things on his
ipse dixit. That's not how the U.S. government works.
