Interpretation #2: Individual Right Theory
The Individual Right theory focuses on the second part of the second amendment: the right of the people part.
The right to own a gun is a right of individuals within a state. It is not a right of the state, as a whole. Nor of any militia formed to protect that state.
Lawmakers cannot enact legislation that prohibits or restricts an individual citizen’s right to possess a firearm. If such laws are enacted, they are presumed to be unconstitutional. Note: This interpretation is paraphrased from the Cornell University Law website (https://www.law.cornell.edu/wex/second_amendment).
The National Rifle Association is the chief proponent and most vocal backer of this interpretation. In this view, there are no real limitations on the kinds of firearms a U.S. citizens can possess. Which is not to say that they are free to buy and use weapons of war, such as grenade launchers and RPGs. The only groups who cannot bear arms, as determined by the courts, are felons and people who are mentally ill. The latter group is the subject of the myriad Red Flag laws that exist throughout the individual United States.
Prior to the 2008 Supreme Court decision in District of Columbia v. Heller, this interpretation had NOT been the predominant one throughout American history. In fact, until that ruling, the rights granted under the Second Amendment had almost always beeen interpretted as applying to militias. As a result, the types and volume of weaponry a person could possess had to be in line with what a militia member might reasonably need.