Originally Posted by AmateurFlix

Well consider for a moment what would happen if the country was so splintered in some way as to actually incite the masses to that level. 300 million civilians vs how many in the standing army? Now do you believe that in such a situation all members of the military would cooperate and follow orders, or would some refuse to serve, some go awol, and other units take the side of the people, bringing with them their equipment? It's not so pointless as it might first seem. (I hope I'm not coming off as some kind of a kook here, that's not the type of event I would ever want to see need to come to pass)

If on the other hand you're talking about some lone backwoods militia group "getting fighting mad", no of course they're not going to achieve anything. There would be little chance of success unless the number of civilians fighting significantly outnumbered the military, and/or some groups within the military would lend support to the people.