This clause was intended to keep Congress from restricting or banning importation of slaves prior to 1808 under its Article I, Section 8 power over “commerce with foreign Nations.” Republicans of the 1790s argued that despite this intention, which was reiterated in several states (notably Massachusetts and South Carolina) during the ratification debates, it applied to all immigration; by this reading, the Commerce Clause grants Congress power to regulate immigration.
I accept this position.
