The tenth amendment constrains congress from regulating outside enumerated powers. Intrastate trade is not an enumerated power. Most applications of the NLRB are tyrannical short-circuits.
First of all, there's no evidence that any of this is intrastate or that Amazon has made a claim on the basis of intrastate trade (this would be a flabbergasting claim for them to make, given that their business is horizontally integrated across 50 states).
Second: the relevant decision here is NLRB v. Jones & Laughlin, which puts it succinctly[1]:
> Although activities may be intrastate in character when separately considered, if they have such a close and substantial relation to interstate commerce that their control is essential or appropriate to protect that commerce from burdens and obstructions, Congress cannot be denied the power to exercise that control.
I'm not aware of a more recent ruling that changes that doctrine.
woodruffw|2 years ago
Second: the relevant decision here is NLRB v. Jones & Laughlin, which puts it succinctly[1]:
> Although activities may be intrastate in character when separately considered, if they have such a close and substantial relation to interstate commerce that their control is essential or appropriate to protect that commerce from burdens and obstructions, Congress cannot be denied the power to exercise that control.
I'm not aware of a more recent ruling that changes that doctrine.