Obviously CA, OR and WA would be first to go.
I am a great admirer of MTG, but in this case she is very wrong.
The first thing that would happen is that those states would be taken over by the Chinese, one way or another, and that would be the first step in the invasion and destruction of our country.
The better way to handle the crazy states would be to declare martial law in those states only and take them over by the US government in a manner similar to the Civil War.
Divide California, as it’s Constitution permits. Put LA ans SF in one State and expel them. Then the electoral landscape for the US changes, which will be an opportunity for increased federalism. If NY or Chicago makes too much trouble, expel them as well.