I'd really rather we didn't throw four months' work on the
Voting Rights Amendment out the window. That resolution, as passed by the House, provides the necessary constitutional support for regional residency requirements.
Beyond that, I must agree with Siren that separating regional citizenship from federal citizenship is a bad idea, and creates a number of practical and ethical problems (most obviously, that some individuals would be obligated to pay federal taxes and follow federal laws without being able to vote for president and Congress). I would much prefer that we continue to abide by the precedent established by the 14th Amendment to the U.S. Constitution; namely, that citizenship (and the rights associated therewith) is a matter of federal policy.