Never heard this argument before. Thom Hartmann:
The real reason the Second Amendment was ratified, and why it says "State" instead of "Country" (the Framers knew the difference - see the 10th Amendment), was to preserve the slave patrol militias in the southern states, which was necessary to get Virginia's vote. Founders Patrick Henry, George Mason, and James Madison were totally clear on that . . . and we all should be too.
In the beginning, there were the militias. In the South, they were also called the "slave patrols," and they were regulated by the states.
In Georgia, for example, a generation before the American Revolution, laws were passed in 1755 and 1757 that required all plantation owners or their male white employees to be members of the Georgia Militia, and for those armed militia members to make monthly inspections of the quarters of all slaves in the state. The law defined which counties had which armed militias and even required armed militia members to keep a keen eye out for slaves who may be planning uprisings.
It's the answer to the question raised by the character played by Leonardo DiCaprio in Django Unchained when he asks, "Why don't they just rise up and kill the whites?" If the movie were real, it would have been a purely rhetorical question, because every southerner of the era knew the simple answer: Well regulated militias kept the slaves in chains.
I'm not agreeing or disagreeing, just passing this one along.
It's always seemed to me that the colonial militias were about rudimentary national defense in a rudimentary age ("security of a free state"). But the entirety of context is easily forgotten 200-plus years later, too.
Got to have a little froth or it's not a cappuccino.