The following is the text of the Second Amendment to the U.S. Constitution:

A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.

As said Lee Z. on TheNation.com: “The 2nd Amendment is about a “well regulated militia”, not about uprisings against the constitutional government of the United States. It was brought in as a way of providing for defense against the British and Native Americans, given that the new nation could not afford, and was fearful of establishing, a standing army (they saw it as a threat to freedom).
The idea that the US Constitution was designed in any way to facilitate uprisings by the citizenry is a gross distortion of the truth, When confronted with Shays’ Rebellion, the US did not defer to it, but suppressed it. The same occurred in the larger Rebellion in 1861, also suppressed. The same would occur with any outburst of citizen gun play “justified” by a claim that the US was a “dictatorship”.
Should the US become a dictatorship, individuals with guns would not be effective in resisting or overthrowing it. This has been shown time and again in wars, where lightly armed fighters are easily overcome by modern armies. Guerrilla warfare can certainly be effective, but it requires wide popular support, and — crucially — allies with modern forces that can aid the guerrillas and deter the guerrillas’ opponents from using all the force at their disposal.
The likelihood that a citizen uprising manned by gun owners would be widely popular in the US is zero. The likelihood of such an uprising finding allies outside the US that could deter the US from crushing the uprising is nil. The only hope for such an uprising would be if the US armed forces went over to their side — very unlikely, but possible. If it did, there would be no need for the uprising, because the armed forces could overthrow the government without much problem (as in Egypt). If the armed forces remain loyal to their chain of command, they would wipe out the uprising in short order. In my opinion, the US armed forces would remain loyal, as they have (with a partial exception in 1861) since the foundation of the Republic.
So the idea of a freedom loving citizenry rising up with their handguns and hunting rifles to “restore freedom” is a ridiculous fantasy, capable of entertaining a fringe of gun lovers and kooks, but completely alien to reality. Some might call it treason if it weren’t such a joke.“

I rather think that if the writers of the second amendment realised that their words were going to be fuel for special interest groups to promote their lethal business ignoring it constituted a profound threat to the first statement of the Constitution itself:

“We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.“

…insure domestic Tranquillity…
…provide for the common defence…
…promote the general Welfare…

… they would have at the very least thought twice about it. 90 guns for every 100 Americans has not shown itself to be very effective to securing any of those rights for 30,000+ shot-dead Americans each year, who in some cases are innocent children.