It’s not much of a surprise to see the Supreme Court strike down the District of Columbia’s gun laws, which had effectively banned handguns and required that any long guns be stored in non-functioning states.

But until the opinions in this closely watched case became public yesterday, it was not clear how emphatically the justices would do so, how much they’d disagree amongst themselves, or how sound their reasoning would be.

During oral argument, Justice Anthony Kennedy worried people when he, apparently seriously, posited that the framers must have had in mind a “remote settler” who needed to “defend himself and his family against hostile Indian tribes and outlaws, wolves and bears, and grizzlies.” However, the decision in District of Columbia v. Heller is good news all around.

Justice Antonin Scalia’s majority opinion forthrightly states that the “Second Amendment protects an individual right to possess a firearm unconnected with service in a militia, and to use that arm for traditionally lawful purposes, such as self-defense within the home.” It strikes down both the gun ban and the requirement of non-functionality.

Equally encouraging is that, while the majority comprised only the bare minimum of five justices, Scalia’s opinion speaks for all of them, with no concurrences. A 6-3 decision would have provided more cushion for the fight ahead, but this is about the best pro-gunners could hope for at this point in the game.

And there is a fight ahead. Since D.C. is a federal enclave, the court didn’t have to decide whether the Second Amendment applies to state and local laws, or just to the national government. Also, we don’t yet know exactly what forms of gun control will fly.

BUT THE OPINION itself, a thorough, well-written, impeccably argued, 64-page mountain of evidence, is most impressive of all.

It accomplishes four important things: It examines the text of the Second Amendment itself; it sifts through the historical record; it parses the language of past Supreme Court decisions; and it makes clear that the Amendment has its limits.

The Amendment’s wording is where most debates start: “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.”

Some have looked at “Militia” and claimed that only militia members have Second Amendment rights, or that all individuals have Second Amendment rights, but only for militia-related purposes. Others have seen “the people” — elsewhere in the Constitution, when “the people” have a right, all the people have the right — and stopped right there.

There are two ways to resolve the apparent contradiction, and Scalia employs both. The first is to remember that, in the Founding era, the militia and the people were basically the same entity.

The second is to put the Amendment’s two phrases into a hierarchy. “A well regulated Militia, being necessary to the security of a free State” simply states a purpose, and can be used for clarification. “[T]he right of the people to keep and bear Arms, shall not be infringed” is what actually describes the right, and should take precedence. Both approaches lead to the conclusion that individual Americans have a right to own guns.

Another way to ascertain the Amendment’s meaning is to look at the historical record, and find clues as to how the Framers’ successors interpreted the words. Scalia provides example upon example of historical documents discussing the Second Amendment in clearly individual-rights terms.

To wit, in 1825, William Rawle wrote, “The prohibition is general. No clause in the constitution could by any rule of construction be conceived to give to congress a power to disarm the people.” Antislavery advocate Joel Tiffany wrote that “the right to keep and bear arms, also implies the right to use them if necessary in self defence.” And so on, ad infinitum.

OF COURSE, on many constitutional issues, the Supreme Court has conveniently “evolved” away from the original meaning. So it became necessary for Scalia to examine the relevant precedent, and look for any inconsistencies with the historical interpretation.

He shows that this is not an issue. In those cases where the court has considered the Second Amendment, it has done so under the assumption that it protects an individual right.

Most important, Scalia makes official what is obviously the correct interpretation of 1939’s U.S. v. Miller. Gun controllers have claimed this decision found the Second Amendment to confer only a collective right. Here is the ruling’s most debated passage:

In the absence of any evidence tending to show that possession or use of a [sawed-off shotgun] at this time has some reasonable relationship to the preservation or efficiency of a well regulated militia, we cannot say that the Second Amendment guarantees the right to keep and bear such an instrument. Certainly it is not within judicial notice that this weapon is any part of the ordinary military equipment or that its use could contribute to the common defense.

It’s clear the issue is what kind of gun the individuals had, not what kind of people the individuals were. If the problem was that men were bootleggers and not militia members, the court would have said that instead of debating whether a sawed-off shotgun is “ordinary military equipment.”

What’s interesting here is that many appellate courts have upheld gun-control laws based on a profound misreading of Miller. With Scalia’s interpretation in a Supreme Court majority opinion, these decisions will be particularly vulnerable to new legal challenges.

In the future, the Court will have to decide where the Amendment’s practical limits are. Scalia by no means solves the issue in toto, but he does much to alleviate concerns about everyday folks running through the streets with machine guns.

The opinion continues the “common use” standard set forth in Miller — the Second Amendment will not protect unusual or particularly dangerous weapons (sorry, guys). Likewise, the justice explicitly directs courts not to construe Heller as striking down restrictions on felons and the mentally ill owning guns, and notes that historically, American courts have often upheld bans on concealed carry.

With such an evenly divided court, conservatives and liberals each win their fair share of victories. But rarely is an opinion on such a controversial topic so incisive, and joined by a majority without a muddle of confusing concurrences.