After mulling this over, my thoughts and instincts are that, the Arizona “shot across the bow” will be identified by future historians as the key incident leading to CWII.
I think Arizona will make a stand on the 2nd and 10th Amendments and all hell will break lose. There will be Citizen Militias deputized, as in the old days of the West, to deal with the border.
This will result in some bloodshed, and Mexico will send its Army into the border, just as they did in the days of Pancho Villa.
Then 0bama will be put to the test: defend America and Americans or defend his PC Fantasy version of the world.
If he does not defend the US, and its constituent states, it is then grounds for removal from office.
Should he be impeached, then we will see, not a region versus region insurrection, but more likely an Urban vs. Suburban/Rural conflict, given that most cities are blue islands in Red states.
Sbmitted for your consideration.
Much like the beginning days of our own Republic in the 1770s. Some had courage and risked everything, others just wanted to stay below the surface of the water, complain a little bit here and there, but not jeoparidze anything and other wise not stand up and take sides when things got hot and push came to shove, and their fellow Americans who DID have courage became under fire, or were rounded up, etc. etc..