Ah, yes, I'd forgotten that detail. The right/obligation to bear arms in defense of your polity has often been the dividing line between citizen and something less. And the Right to Keep and Bear Arms came up in several places in the Dred Scott decision.

Related, I was just reading something about the history of the fall of the Roman Republic, about a threshold where a class of men without significant economic means were allowed to enlist, which lead to them being dependent on their general's largess, and developing allegiance to him instead of the Republic.