This is an interesting discussion, I think should that day come you will find that history has shown there are citizens out there that though ill equipped and silent, can provide quite a pocket of resistance because they are mentally & physically up to the task, not because of weaponry. History has also shown that pouring money into "just in case" weaponry without mental and physical preparation will not gurantee victory and if you are not wired for battle that the guy next to you will be yelling and kicking you to get you to pull the trigger.  So that fancy rifle a guy bought to protect the home front might make them feel better, but isn't worth anything if they are not wired to stop a threat (more likely multiple threats) under high stress. The active shooters we read about are successful because they shoot unarmed victims and there is no resistance. Once they encounter resistance they often take their own life...because they are not wired for "battle". Statistically only a small percentage of people are willing to commit violent acts, so when the movement starts, one best hope that at least 1/4 the people on your team are prepared and trained to stay on for the full 8 second ride or you are in big trouble.
Food for thought, you are looking at a country that was able to clear a nation's store shelves of toilet paper in 24 hours due to a threat of a RESPIRATORY virus, call 911 because they were shorted a chicken nugget, compare a business owner requesting they wear a mask in a store to being herded onto train cars and headed to a govt camp, and...many of these people are buying guns and ammo at historic levels because of fear of govt over reach. Hardly what I'd call a "militia", and definitely not a nation of "live free or die" types. That's why if this all goes down I opt to head for the hills to live free and enjoy some venison around the campfire watching the smoke columns in the distance rather than lining up alongside 911/chicken nugget guys to storm the nation's capital on a suicide mission so I can keep my guns. Hell, I didn't even buy any guns this year! I suppose that makes me anti 2A? Maybe it does, or maybe I'm just not scared enough to panic just yet and know there is much more to survival than possession of your gun. That being said, invade my personal space to do harm to me or my family/friends whether govt or otherwise and I'll cross the bridge if I get there, but I can assure you gunfire is only one of many options on the table to stop a threat under those circumstances.