Because there was essentially nothing in between 1789 and the rise of the modern "gun rights" movement starting in the 80s to support it. The current interpreta

Because there was essentially nothing in between 1789 and the rise of the modern "gun rights" movement starting in the 80s to support it. The current interpretation would have been completely preposterous in the 60s and 70s. Just see how gun laws were used against the Black Panthers in the 60s.