The Supreme Court cast aside the 1939 precedent of Miller, and when the makeup of the court changes this year, Heller could be revisited as well.
The original text of what became the Second Amendment, as brought to the floor of the House of Representatives in the first session of the First Congress read: The right of the people to keep and bear arms shall not be infringed; a well armed and well regulated militia being the best security of a free country; but no person religiously scrupulous of bearing arms shall be compelled to render military service in person.
The Bill of Rights introduced by James Madison was not composed of numbered amendments intended to be added at the end of the Constitution. Instead, the Bill of Rights was to be inserted into the existing Constitution. The sentence that became the Second Amendment was to be inserted in Article I, Section 9, between Clauses 3 and 4, which list individual rights, instead of Article I, Section 8, Clauses 15 and 16, which specify the Congress's power over the state militias.
Debate in the House focused on whether a Bill of Rights was appropriate, and the matter was held for a later time. Madison raised the issue of his Bill and proposed a select committee be created to report on it. The House voted in favor of Madison's motion, and the Bill of Rights entered committee for review.
No official records were kept of the committee's proceedings, but the committee returned to the House a reworded version of the Second Amendment. That version was read into the Journal: A well regulated militia, composed of the body of the people, being the best security of a free State, the right of the people to keep and bear arms shall not be infringed; but no person religiously scrupulous shall be compelled to bear arms.
The Second Amendment was debated and modified during sessions of the House. These debates revolved primarily around risk of "maladministration of the government" using the "religiously scrupulous" clause to destroy the militia as Great Britain had attempted to destroy the militia at the commencement of the American Revolution.
These concerns were addressed by modifying the final clause, and the House sent the following version to the U.S. Senate: A well regulated militia, composed of the body of the people, being the best security of a free state, the right of the people to keep and bear arms shall not be infringed; but no one religiously scrupulous of bearing arms shall be compelled to render military service in person.
The next day, the Senate received the Amendment from the House and entered it into the Senate Journal. When the Amendment was transcribed, the semicolon in the religious exemption portion was changed to a comma by the Senate scribe.
The Senate voted to change the language of the Second Amendment by removing the definition of militia, and striking the conscientious objector clause.
The Senate returned to this Amendment for a final time. A proposal to insert the words "For the common defense" next to the words "Bear Arms" was defeated. The Senate then slightly modified the language and voted to return the Bill of Rights to the House. The final version passed by the Senate was: A well regulated militia being the security of a free state, the right of the people to keep and bear arms shall not be infringed.
The House voted on September 21, 1789 to accept the changes made by the Senate, but the Amendment as finally entered into the House journal contained the additional words "necessary to".
The final version read "A well regulated militia being necessary to the security of a free State, the right of the People to keep and bear arms shall not be infringed". This was the version transmitted to the states for ratification.
The individual rights viewpoint did not emerge until several decades after the Second Amendment was drafted.
In 1905, the Kansas Supreme Court in Salina v. Blaksley made a collective right judicial interpretation. The Kansas high court declared: "That the provision in question applies only to the right to bear arms as a member of the state militia, or some other military organization provided for by law, is also apparent from the second amendment to the federal Constitution."
The true (and only) subject under active debate when the 2nd Amendment was framed was the militia.