A disorganized, fractured effort would be less likely to be successful than an organized, concerted effort. It could take the shape of certain States being taken over by militiaa within that state. The idea of a unified, national movement occurring, seems very unlikely. Some of the middle America States could probably easily be taken by the massive militias within them.

Certain States might declare independence from the US government, and the national guard, sheriff's associations, and various other armed law enforcement and military bodies could support that effort. It seems like there's many states within America that don't need to be taken over by an armed group, as they would be amendable to it anyway.