That militia mentioned in the Second Amendment wasn’t meant to supplement the military. It refers to state militias, which were supposed to be the military. From Ryan McMaken at mises.org:
The phrase “pro-gun, pro-military” is used by some conservatives to describe themselves, as if the two go together seamlessly. For example, activist and political candidate Erin Cruz states she is both “Pro Second Amendment” and “Pro Military” in her promotional materials.
Another Republican candidate, Gregory Duckworth, advertises that he advances “pro-gun and pro-military initiatives.”
And last year, Donald Trump, Jr. — as part of a controversy over Keurig coffee pulling its advertising from Sean Hannity’s show — denounced Keurig and endorsed Black Rifle Coffee, which is advertised as a company with a “pro-gun and pro-military stance.”
