From his On Second Opinion Blog, The Mason Triad Context of Second Amendment Development and Purpose: Barriers Against Power in All Forms and Departments of Government:
The citizens in 1789 relied on flintlock firearms just as the soldiers of a period army. At that time, a standing army in time of peace was the face of tyranny. Today, the face of tyranny is just as common in the world, but is much more intrusive and dangerous, and is usually referred to as a police state. Americans have the constitutional right and duty to prevent the establishment of any police state in the United States. The people must keep their government under their control, which is accomplished, not by fighting, which is only a last resort, but by making certain that violations of the Constitution by those at the helm of government are challenged and reversed.
In the modern world, government raised forces, whether troops or police, are not armed with flintlock firearms. Police forces always carry modern arms. The purpose of such arms is self-defense. Every American citizen is guaranteed the same right by the Second Amendment. In order for Americans to keep their government and its forces under their control, as the Constitution guarantees, the people, at a minimum, have the right to keep and bear the same type of arms that police are provided.
RTWT. David has the distinct advantage of being able to make his point quickly and with ironclad references.