The Limiting Principle of Interstate Commerce

i suspect that in most cases when it comes to congressional action they decide on the law and then come up with some post-hoc justification. i feel like any bill that is ever passed almost certainly somewhere has some boilerplate footnote written 50 years ago saying oh by the way we're doing this based on the commerce clause. There have been a few recent cases that have shifted the the test for whether something falls under interstate commerce just a bit.