I'm sorry to have to burst their bubble--well, not really--but the
legislative history following the Second Amendment's passage very
clearly supports the opposite of what they say. In 1789, the militia was
intended to substitute for a standing Army, and to defend the
government from insurrection.
Congress passed two Militia Acts in
1792. The first created state militias, each under control of that
state's governor, specifically created to resist invasion, and suppress insurrection
. The second directed all able-bodied white men between the ages of 18
and 45 to belong to their state militia, own a gun and related equipment
for that purpose, and report for duty twice a year. The law even laid
out how many bullets each militia member had to bring with him--25 if he
owned a musket, 20 if he owned a rifle. After the Civil War the Acts
were modified to allow black militia members to belong. In 1903, the
state militias were merged with the National Guard.
Aside from frontier fights with the Indian Nations, the militia was
used only twice between 1792 and 1814: Once against the Whiskey
Rebellion in western Pa. (led in person by George Washington); and then
at Bladensburg, Md., to defend Washington DC against the British (the
militia ran at the first volley and the day has been called the
Bladensburg Races ever since). There was one use of a militia under the
Articles of Confederation; in 1787, Shay's Rebellion in western
Massachusetts was put down by a private militia after Shay's men
attacked the Springfield armory.
There is no record of any legally-constituted militia "defending the
people against a tyrannical government" under the Constitution--acts it
would construe as treason, under Article 3, Section 3 ("Treason against
the United States, shall consist only in levying War against them, or in
adhering to their Enemies, giving them Aid and Comfort.") The only way
to claim otherwise is to use the Civil War as an example. Even then,
using state armies that way fit the Constitution's definition of
treason; it was simply expedient after the war to let the matter go.
Given that, anyone can see that the militia under the Constitution
was an instrument of the state from the first, and never meant to
safeguard the people from the state. What the NRA is doing is trying to
confuse colonial militias--when there was no United States--with
militias under the Constitution.