[gaur]

The creation of Maine from Massachusetts shows that there is a way to redraw the borders of a state already admitted to the union. It may not be an efficient or repeatable process, but evidently it can happen regardless of how many times you say "states, not provinces!".

[koenigdavidmj]

Importantly, this was only done with the consent of the state.

[AnimalMuppet]

I'm not sure that West Virginia came out of Virginia with Virginia's consent...