A movement to ban handguns began in the 1920s in the Northeast, led by the conservative business establishment. In response, the National Rifle Association began to get involved in politics, and was able to defeat handgun prohibition. Gun control and gun rights became the subjects of intense political, social, and cultural battles for much of the rest of the 20th century, and into the 21st.

Often, the battles were a clash of absolutes: One side contended that there was absolutely no right to arms, that defensive gun ownership must be prohibited, and that gun ownership for sporting purposes could be, at most, allowed as a very limited privilege. Another side asserted that the right to arms was absolute, and that any gun control laws were infringements of that right.

By the time that Heller and McDonald came to the Supreme Court, the battles had mostly been resolved; the Supreme Court did not break new ground, but instead reinforced what had become the American consensus: the Second Amendment right to keep and bear arms, especially for self-defense, is a fundamental individual right. That right, however, is not absolute. There are some gun control laws which do not violate the right, particularly laws which aim to keep guns out of the hands of people who have proven themselves to be dangerous.

In the post-Heller world, as in the post-Brown v. Board world, a key role of the courts will be to enforce federal constitutional rights against some local or state jurisdictions whose extreme laws make them outliers from the national consensus.