Re: Some residents of Vermont want to secede - End of USA?
Sorry this is unrealistic. The US civil war showed clearly that federal powers are greater then state rights. To secede from the union is not allowed, and would never be tolerated. When Lincoln said "the union of these states is perpetual" (I am paraphrasing here), it applied for alltimes.
Besides, other secession movements have sprung up from time to time (NY during the CW to keep the southern market open) but are always shot down or lose steam.