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.

While conventional wisdom suggests that an individual’s right to bear arms is enshrined in the Second Amendment of the Constitution, it is, in fact, a relatively recent interpretation, according to New Yorker writer and legal analyst Jeffrey Toobin.

As politicians weigh new gun-control legislation in the wake of Friday’s brutal shooting in Newtown, Conn., FRONTLINE spoke with Toobin, author of The Oath, about what he describes as “the conservative re-casting of the Second Amendment” and whether potential new gun control laws could conflict with it.

Describe early understandings of the Second Amendment. Was there uncertainty or ambiguity about what it meant?

The overwhelming consensus was that the Second Amendment gave state militias a right to obtain and bear arms, but it did it not give individuals any rights. … The words of the Second Amendment are ungrammatical and difficult to understand in the best of circumstances. But if you look at the history and context of the amendment, including other references to state militias in the Constitution, it suggests that the amendment only applied to state militias.

“It was simply taken as a given in constitutional law that the Second Amendment did not give individuals a right to bear arms.”

Now what makes this subject so difficult in the modern world is that state militias don’t exist anymore, so we have no familiarity with what a state militia is. But it was simply taken as a given in constitutional law that the Second Amendment did not give individuals a right to bear arms.

When and how did that understanding begin to change to reflect an individual’s right?

It really started to change with the rise of the modern conservative movement in the ’70s and ’80s. You had Ronald Reagan, Edwin Meese, who was his attorney general, Orrin Hatch (R-Utah) in the Senate, really making a very sustained argument that the courts had misunderstood the Second Amendment for hundreds of years, and the NRA was an indispensable partner in this moment. And it became the conservative conventional wisdom that the Second Amendment gave an individual the right to bear arms.

1977 is really a key moment here, because that’s when the National Rifle Association went from being a largely apolitical gun-safety organization to a mobilized political operation that was dedicated to fighting gun control. … It both reflected and reinforced the growing conservatism of the Republican Party generally.

You had Orrin Hatch, when he was chairman of the judiciary subcommittee, putting forth a major report [PDF] that said all the courts were wrong about the Second Amendment. You have Clarence Thomas on the Supreme Court starting to advocate a renewed understanding of the Second Amendment. The country appears to have gotten more sympathetic to the argument that guns make people safer, not more dangerous.

The idea that the Second Amendment gives individuals a right to bear arms was advocated so forcefully, so broadly and so persuasively that Democrats gave up on fighting the issue.

In your book The Oath, you explore how even then-Sen. Barack Obama took on this individual rights understanding and walked back some of his earlier views on gun control. What does that convey?

I think Obama personally illustrates how much the individual rights view has evolved into the conventional wisdom even for Democrats.

Now, I think Obama and at least some Republicans would differ about the extent of what the Second Amendment represents, but I think Obama’s embrace of the individual rights theory illustrates how pervasive that theory has become.

How did these efforts to recast the amendment culminate?

… The climax of this reinvention of the Second Amendment came with the [District of Columbia v.] Heller case in 2008 with the Supreme Court when it reversed decades of precedent and [gave] individuals a right to bear arms. What the court left unclear was how extensive that right was.

“The country appears to have gotten more sympathetic to the argument that guns make people safer, not more dangerous.”

What Heller says is that you have a right to a handgun in your home. It does not say anything about assault weapons. It does not say anything about concealed weapons.

So the limits — and it does suggest there are some limits, like you can’t have a tank, you can’t have a Stinger missile — but the courts are really struggling now with defining what the limits of the Second Amendment are.

Some legislators, like Sen. Dianne Feinstein (D-Calif.), have promised to introduce new gun-control legislation that could ban particular weapons in the next session. What’s the likelihood of such laws conflicting with Heller?

I think there’s considerable ambiguity at the moment about what’s constitutional and what’s not. Now that didn’t used to be the case. All through the ’60s and ’70s, we had arguments about how much gun control was appropriate, but no one suggested that any of it was unconstitutional.

Now we have two levels of arguments: What is the right level of gun control and is it constitutional? It’s uncertain about their constitutionality today.

On Meet the Press on Sunday, Sen. Feinstein said her plan to introduce legislation similar to the now-expired assault-weapons ban wouldn’t conflict with the law, saying: “The National Rifle Association never brought the ‘94 assault weapons legislation to court. They knew it would be sustained from the beginning. And I believe this will be sustained as well.” Is she right?

The assault weapons ban ended in 2004, which was before Heller. My guess is that an assault weapons ban would be constitutional, but you would get a powerful argument on the other side.

This is political as much as legal. This is about justices who come out of the conservative movement advocating positions that they’ve advocated for a long time. And what the Second Amendment means is not determined by the Second Amendment, it’s determined by who wins presidential elections and gets to appoint their like-minded justices.

These decisions about what the Constitution means are deeply political. Always have been, always will be.