Suppose a Seung-Hui Cho, Jared Lee Loughner, James Eagan Holmes or an Adam Lanza shot and killed or seriously wounded any of the families of John Roberts, Antonin Scalia, Anthony Kennedy, Clarence Thomas and Samuel Alito. Would any of them have given different opinions in their 2008 and 2010 decisions?

Virginia Tech student Seung-Hui Cho, 20, shot and killed 32 people and wounded 17 before killing himself, on April 16, 2007. Cho’s weapons: a German-made Walther P22 semiautomatic pistol and an Austrian-made Glock 19 semiautomatic pistol.

Jared Lee Loughner, a 22-year-old student, shot and killed 6 people and wounded 14, at a congresswoman’s public meeting with her constituents near a supermarket in Tucson, Arizona, on Jan. 8, 2011. Loughner’s weapon: a Glock semiautomatic pistol.

James Eagan Holmes, a 23-year-old student, shot and killed 12 people and wounded 58, at a movie theater in Aurora, Colorado, on July 20, 2012. Holmes’ weapons: U.S.-made Remington 870 Express Tactical shotgun, a U.S.-made Smith and Wesson M&P semiautomatic rifle and an Austrian-made Glock 22 semiautomatic pistol. “M&P” stands for “military and police.”

Adam Lanza, 20 years old, shot and killed 26 people, 20 of them children 6 and 7 years old, before killing himself, at an elementary school in Newtown, Connecticut, on Dec. 14, 2012. His weapon: a U.S.-made Bushmaster XM-15 semiautomatic rifle.

Roberts, Scalia, Kennedy, Thomas and Alito are the five Supreme Court justices who, on June 26, 2008, in District of Columbia v. Heller, declared unconstitutional the district’s “law [banning] handgun possession by making it a crime to carry an unregistered firearm and prohibiting the registration of handguns.”

Then, on June 28, 2010, in McDonald v. Chicago, the same justices cited this very decision to declare unconstitutional the laws of Chicago and the village of Oak Park “effectively banning handgun possession by almost all private citizens.”

On what grounds was their 2008 decision based? The Second Amendment of the U.S. Constitution, which is more than 200 years old. It says in its entirety: “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.”

Antonin Scalia, who wrote the opinion of the court, asserted: “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.

“The Amendment’s prefatory clause announces a purpose, but does not limit or expand the scope of the second part, the operative clause. The operative clause’s text and history demonstrate that it connotes an individual right to keep and bear arms.”

Scalia, who makes, outside the court, pronouncements so mindless as to make one wonder why no one in Congress has called for his impeachment, did not just make a semantically questionable interpretation; he trampled on precedent, when precedents are what conservatives like him are supposed to uphold.

The precedent here was the single Supreme Court decision dealing directly with the Second Amendment before the 2008 decision, U.S. v. Miller in 1939. Clark McReynolds, an archconservative with fundamentalist bent, wrote the opinion, stressing the surpassing importance of “the Militia” in understanding the Second Amendment. To illustrate “the signification attributed to the term Militia,” he quoted from “the debates in the [Constitutional] Convention” in 1787, the Constitution “as originally adopted,” as well as “the history and legislation of Colonies and States, and the writings of approved commentators.”

Among the “approved commentators” were Sir William Blackstone and Adam Smith. Blackstone’s “Commentaries on the Laws of England” is a series of treatises on common law that Abraham Lincoln, among others, closely studied as an aspiring lawyer. Smith’s “Wealth of Nations” is one book that American business titans and conservative politicians love to mention, as John Kenneth Galbraith once quipped, without ever reading it.

It was McReynolds’ 1939 decision that the solicitors general under two recent Republican presidents, Ronald Reagan and George H.W. Bush, cited to reach their judgments on the Second Amendment.

Thus, Charles Fried affirmed that “the Second Amendment guarantees no right to keep and bear a firearm that does not have some reasonable relationship to the preservation or efficiency of a well regulated militia.” Likewise, Kenneth Starr, later of Monica Lewinsky fame, asserted that “the possession of [a] firearm did not fall within the rights guaranteed by the Second Amendment.”

U.S. solicitors general represent their administrations’ legal views. Yet Antonin Scalia dismissed all this as “of dubious interpretive worth” — yet another example of a justice citing precedents and legislative histories when they suit his purpose.

On Dec. 11, just 3 days before a young man shot dead 26 people in Connecticut, the Seventh Court of Appeals struck down Illinois’ ban on carrying concealed weapons as unconstitutional. The precedent cited was the 2008 Supreme Court decision by Scalia et al.

A quick tally USA Today made upon the news of the Connecticut “massacre” showed that from 2006 to 2010, there were what the FBI says were 156 “mass killings,” where four or more are killed, for a total of 774 people, including 161 children. Thus, during the five years, “mass killings” occurred every 1.7 weeks in this country.

The Virginia Tech Massacre — “the deadliest shooting incident by a single gunman in U.S. history” — occurred in April 2007. Yet, a little over a year later, five justices on the Supreme Court declared gun control unconstitutional. And two years later, after many more mass killings, they affirmed their decision.

Hence the question: Would any of the justices have interpreted the Second Amendment differently if any of their families were shot dead or seriously injured? One may also ask: Are laws in the United States going out of control?

John Adams, the second U.S. president, is known to have written in his draft of the Constitution of Massachusetts in 1779 that the government of his commonwealth would be “of laws, and not of men.” This observation is often cited as the wisest ever made of the U.S. as a society of law — when things turn out well. But it is self-evident that men make laws and men manipulate laws. With regard to gun possession, things have turned out very badly indeed.

Why don’t American people recognize that it is well nigh impossible for one person in a normal course of civilian life to kill one, two, three, let alone 20 or 30 people all at once, without a gun?

Hiroaki Sato is a translator and essayist in New York. His biography of Yukio Mishima with Naoki Inose, “Persona,” has just been published.