If they don't, they should (I'm not a gun owner or an NRA member). If you look at history, it is exceptionally rare to find a 100 year stretch where governments and militaries didn't kill more civilians than any amount of murderers. Not always domestic governments, but that only adds to the point.
> if things got so bad that the government was "turning on its own people" with weaponry, somebody really thinks some guys with guns from Wal-Mart are going to be what stops them?
I'm not going to speculate, but it might not be as one sided as you'd think. Put all the hunters in the U.S. together and you have the largest army in the world by a factor of five.
Regardless it doesn't have to be that bad. Government apathy or corruption can be enough to justify retaining the right to self defense. Consider the police work slowdown in NYC turning into a thinly veiled version of protection money. Local LEOs that ask for more money every year or 'gee I guess we will have to just let everyone out of jail'. Or consider something like that judge that sold children into private prisons. Imagine that despite protests and uproar, they sweep it under the rug and continue? History is rife with examples of people being exploited simply because they were dependent or defenseless.
Someone who has your best interests in mind won't demand that you be defenseless or dependent upon them.
Since then it seems like federal law enforcement has taken a softer touch with their sieges. This could be simply a change in doctrine to avoid bad press but enough people believe it's more than that.
Also, these days it isn't so much about guys with guns from Wal-Mart as it is country boys that did a couple tours in IQ/AF as a 11something and their friends. <digression> That's also why the NRA is touchy about funding for studies on things--there's a perception that "the powers that be" want to diagnose everyone who served with PTSD and then use that as a reason to take away their guns. This is compounded by some despair over disarming IQ villagers so they are easy pickings for ISIS and the perception that "they were training us to do it back home". </digression>
So, yes, I believe it. Because I'm seeing it happen.
Sympathy from the armed forces and various forms of political pressure, foreign and domestic, would be far more helpful than a few deer rifles, and if you've got that your private arms aren't really necessary. A domestic rebellion wouldn't win by shooting enough people, it'd win when the tactics necessary to stop it were beyond what the government and/or military were willing to do.
Guns are much more useful when:
1) the enemy is foreign (killing enough people actually might make them go away), and/or
2) your position doesn't actually have popular support so other means are unavailable to you, and/or
3) foreign powers have the will and capacity to bomb the shit out of your country if the government goes too far in its attempts to suppress your uprising (this, or loss of military support for the government, are basically the only reasons authoritarian states fail to stop revolutions in the modern world)
Actually, having closely studied the dissolution of a modern European country (the former Yugoslavia) and seen the fallout from up close, it's not that simple (at least not always).
What happened in that case was that although the Yugoslav government [1] retained control of most of the heavy weaponry (artillery, tanks), and although the succeeding republics (Croatia and Bosnia) were initially limited to small arms belonging to local militia and hunters, the republics did have an abundance of active and retired officers with loyalty to their ethnic homelands who were quick to raise and lead battalions of troops into the field [2].
Those troops then went on to capture some heavy arms from the Yugoslav army, and scored lots of small arms, and eventually heavy arms and aircraft, from overseas allies.
Eventually, after lots of brutal warfare, ethnic cleansing, and in Bosnia, genocide, the republics did gain their independence from Yugoslavia (with significant help from the U.S. and other countries).
What was key in this case were the experienced military leaders who quickly assumed charge in the succeeding republics.
I suspect a worst-case, nightmare U.S. scenario would look much the same, with experienced military leaders taking control of ad hoc forces in their respective states and/or regions, and then fighting with small arms until they were able to capture heavy arms, receive outside help, or were defeated/captured.
1. Essentially, Serbia and Montenegro, plus ethnic Serbs elsewhere
2. Slovenia's succession was a different story than that of Bosnia and Croatia, for a variety of geographical, cultural, and historical reasons.
The more realistic scenarios don't actually involve the military itself turning against the people. It's far more likely that police will overstep their bounds a little and try to go house to house, and one reason they don't do that, outside of exceptional circumstances that the public will back them up on, is the fact that doing so is actively dangerous.
As for "guys with guns from Wal-Mart" in the US, let's not forget that we have tens of thousands of experienced returned officers and NCOs, who are very knowledgeable about guerrilla warfare and who identify very strongly with that rural population base here in the US.
Also, look at the Nazi invasion of the Island of Crete. A ton of local farmers with gun took a huge toll on the Nazi paratroopers.