The people. Anti-Gun Control folk always like to say "How are your guns supposed to defeat the government's tanks and bombers and drones" Bitch please. Do you not know what happened in Vietnam, or Iraq and Afghanistan for that matter?

No matter how well trained your troops are or what shiny toys you have fighting an insurgency is really fucking hard. Fighting American insurgents will make the Vietcong look like a cake-walk. The Vietcong were illiterate farmers using crappy surplus guns from China. Cletus and Hosiah have guns even better than what some of the actual soldiers can get their hands on, and have been waiting to shoot some Feds with it their entire life. You really think a soldier's training and big scary vehicles are going to be enough to deal with everyone and their dog gunning down an entire squad every 100 feet?

Then there's the fact that not only would the US Government be fighting an insurgency, but they would be fighting an insurgency on their own turf. The US military isn't localized like it was in the first Civil War, which means every unit is going to have someone who grew up near, or even with, today's group of insurgents shooting at their platoon. You really think every soldier is going to stay loyal when they find out that tomorrow they're going to have to blow up their home town? Of course not. There will be mass desertions at best, and outright treason at worst.