TexasRifleman, I've taken quite a few history classes in high school and college. I have an interest in military history outside of school which I feel has added more to my education than the classroom though both have been worth while investments of my time.
We won all the battles in Vietnam, but lost the war stateside. It was in this country and not in Vietnam that we lost the war. The American people weren't for the war, so we pulled out.
In Afghanistan, with the aggressor being the former Soviet Union, their "Vietnam" was largely lost because the USSR was collapsing in on itself.
In Afghanistan and Iraq, with the aggressor being the United States, like Vietnam, we won every battle (and still do). When an Iraqi or insurgent picks up a rifle and points it in our direction, he gets his butt handed to him by an American rifleman, tank gunner, pilot, and so forth.
The Japanese during World War II used similar guerilla tactics as the Viet Cong, Afghanis, Iraqis, and insurgents; however, with great losses of American servicemen they did not prevail against the superior technology and greater power of the United States.
You could argue that the guerilla tactics by the Viet Cong against the United States and the Afghanis against the former Soviet Union hastened the collapse of the USSR and the pull out of American forces from Vietnam. In that sense, the guerilla fighters were successful against a superior force.
In a second American revolution, we would be fighting against our own military, which is the most technologically advanced military ever devised by man. We would need far more than a handful of civilians with battle rifles against such a foe.
Night vision, as one example, is a start. Our military controls the night and never allows our enemy to rest easy. An ability to communicate without government surveillance would be step number 2. Tinfoil hats don't work so well.
TexasRifleman argued that it's conceivable that some individuals in the corrupt government forces would refuse to obey unlawful orders justified by their oath to "defend the Constitution of the United States against all enemies, foreign and domestic." It's also conceivable that a corrupt government and the states would ratify several amendments that redefine the Constitution. Take the 16th Amendment for example,
The Congress shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration.
They opened up a can of worms with that one. At one time the majority of the tax came from tariffs on imported goods (sounds like a good idea to me!). Now we tax everyone and everything and every income from cradle or grave.
As another tidbit of history, The Socialist Labor Party advocated for a graduated income tax in 1887 and The Populist Party "demanded a graduated income tax" in their 1892 platform. Interesting facts aren't they?
In this scenario, government forces who took an oath to defend the Constitution would be doing just that and could not refuse the order to obliterate the future revolutionaries.
Everyone has their own interpretation of the 2nd Amendment. The largely universal interpretation is that it protects an individual right to own firearms; However, there's no doubt that even with ownership of firearms, it would be damn near impossible for civilians to defeat a standing army as large and powerful as the United States military. 10 points to the one who points out the Federalist paper that argues against a standing army.
The 2nd Amendment, by my interpretation, is a window or crystal ball into the status or level of liberty in the United States. The greater the government trusts the American people with firearms the greater our liberty. Likewise, the less the government trusts us with firearms, the less our liberty.
Gun control is almost always a series of measures or steps in a platform of "reform." A platform of reform including gun control includes a lot of other measures of lessening liberty such as increased taxation, increased government control of education, and so forth.
Abridged edition:
By my interpretation, the 2nd Amendment and ownership of battle rifles or other firearms offer not a practical defense against a tyrannical government, but rather, a symbolic and moral scale with which to judge if we're still a free nation.