[ovidnis]

Are those two equivalent though? As I understand the Schengen Area is about freedom of movement whereas the Commerce Clause is about, well, commerce.

[germanier]

No, they are not really. Schengen is mostly about border controls. For example, Switzerland is in Schengen but they are not part of the EU customs zone, so goods cannot be freely moved across the border (although there are a lot of bilateral treaties to make this easier).

But the EU has their own version of the Commerce Clause, the Common Market.