I know from that many think Congress power deals only with non-Americans becoming Americans. But, it is obvious that one must define US citizen in order to determine those who require being naturalized.
The final lines of section 8 are enormous, “make all laws necessary”. When it comes to determining naturalization laws, Congress is empowered by the Constitution to make all laws necessary.
Just as much as you must define ARMS before people can exercise the right guaranteed under the 2nd amendment.
But wait. Are we sure we want congress to have the power to define ARMS? What if they change the definition to something other than what the founders intended?