There is no way to know what will occur. The Mexican army might invade Texas, who can say for sure.
The northeast is full of immigrants and not everybody is getting along so well. This isn’t just about the border states, when the shooting starts it is going to be who is black, white or brown. Everyone will seem like criminal because of all the shooting and looting. It’s not going to matter who shows up in front of you, you’re not going to trust them.