Fighting the government is an idiotic point to make for miltias/2nd amendment supporters.
1) It's highly, highly, HIGHLY unlikely that was the actual intended purpose of the 2nd amendment by those who injected it into the constitution. First, they actually disliked militias. Their intent was certainly not, "Let's allow these ragtag ill-disciplined shitlords to shoot up the government". The only time militias have actually been used to good effect in the entire history of the country, was when Washington sent militias to shoot up, what we today would call "sovereign citizens" in the Whiskey Rebellion. Ironically, the very type of people the modern militia movement revolves around, were the very people militias were used against in the ONLY instance in American history where militias were actually successful. As it turned out, these "sovereign citizens" that staged the whiskey rebellion, threw down their arms and surrendered the moment the militias arrived.
2) Even if there was some intent for militias to "regulate" the government, as silly as that concept is, that regulation ended with industrialization. It's one thing for a band of irregulars armed with musket and flintlocks and other relatively primitive weapons to engage government forces in an irregular manner, when both sides are largely using the same weapons. It's another entirely when the height of military technology that these militia groups are going to be using, are assault rifles, military surplus style WW1 era machine guns, bootleg explosives, and ghetto off the shelf drones. What happens if there is ever a real armed militia insurrection? National guard F16's are going to drop JDAMS on them from 20-30k feet. Predator and Global Hawk drones are going to light them up with hellfire ATGMs.
The REAL purpose of the 2nd amendment, was really, to protect the country from domestic threats, to serve as sort of a pre-cursor national guard, and more importantly, as a levy against FOREIGN threats.
The founding fathers had such a low opinion of militias, that it's hard to really state it without hyperbole. Washington himself in his dispatches said he loathed the militias, and on one occasion threatened to start slashing them down mid battle because they were retreating, refusing to fight, and wouldn't get off the road which was hampering the regulars from using it.