Someone might register before achieving full citizenship on the assumption that citizenship at the time of the election is good enough -- just as it is possible for someone to register at age 17 so long as one turns 18 on or before Election Day. We should all know about that.
I don't know if it is the case everywhere, but in South Carolina, not only can 17 year olds register, they can vote in primary elections so long they will be 18 when the corresponding general election is held.
This is true in IL starting this year.
Michigan has this rule as well. It makes sense to me.
I'm pretty sure that's the rule in VA as well.
