Unless, of course, the rabid ideologues insisted on fighting one. However, you didn't use the word "extended." Adding that qualifer, I quite agree with you--it would not take very long for any such war to be wound up, as the number of people who are both stupid and crazy enough to start it is very low.
Any gathering of them sufficient in numbers and training to require a military detachment (as opposed to law enforcement) to deal with them would probably represent a significant total of their operational forces, and would effectively end the military phase of the campaign.
I think you are mistaken in thinking they wouldn't wage war against their own people. I used to think otherwise, but recently I've come to the conclusion that we've passed the point of no return. We're going to get the dictatorship that the american people seem to be demanding, and there isn't a thing you or I can do about it.
Only a relatively few of us will not submit quietly, and we'll be labeled 'terrorists' or whatever else the Fedgov/media conglomerates feel like calling us, and the rest of the sheeple will go along willingly as long as they can have a temporary illusion of safety.
That's not how it works. The military is used to quell any large disturbances and the civilian authorities do their thing from behind the shield of the troops. That's exactly what happened in 1967 at the Pentagon. A company of Combat Engineers repelled a violent group of antiwar demonstrators and established a line with the peaceful demonstrators. Once things calmed down, some Federal Marshals used our line to snatch some sit-down demonstrators from the crowd. Their targets were apparently at random and they seemed to like teenaged girls. They weren't reluctant to use their billy clubs.