Why is the Second Amendment important? Because of the Third Amendment.

First, let’s deal with less-lofty matters.

It’s not hard to understand that if you’re attacked, or someone breaks into your home while you’re watching TV, dialing 911 isn’t the best way to defend yourself and loved ones.

To bolster your self-defense, you could remind your attackers that President Barack Obama says they shouldn’t have guns, and if he finds out that they do, they’ll be in big trouble. He might ban them from flying on airliners. That probably won’t be any more persuasive than asking them to wait while you call a cop. Thugs bold enough to attack you or kick in the door to your home aren’t going to freeze while you dial your phone.

Then there’s this, according to the law enforcement magazine American Police Beat: The average response time for emergency calls is 10 minutes. What could go wrong in 10 minutes while you’re scolding the bad guys and reminding them of Obama’s threat?

That’s why, intuitively, it’s better to be armed than sorry. That’s also why sheriffs across the country increasingly urge people to arm themselves against possible terrorist attacks, let alone garden-variety degenerates accosting them on the street or breaking into their homes.

“Violent criminals can take our lives in seconds,” said Sheriff Wayne Ivey of Brevard County, Fla., warning that waiting on a 911 response is unwise. The massacre at a workplace Christmas party in San Bernardino was all over, with 14 dead and the shooters fled, by the time police arrived, a scant four minutes after being called.

“We should allow people … to be able to play a role in their own safety,” agrees Sheriff David Clarke of Milwaukee County in Wisconsin. “These gun-free zones have become killing fields.”

This commonsense, pragmatic conclusion is not only reasonable, it can be life-saving when people arm themselves for protection. Experience and experts agree.

Now, about those lofty matters.

Start with the basis for statutory law: the U.S. Constitution. “The founding fathers never intended for the government to be stronger than its people, capable of suppressing its citizens by force,” says Eric R. Poole, editor of Guns & Ammo magazine.

That’s probably not the first thing that comes to mind for most Americans when discussing gun ownership, gun rights and gun “control.” How far we have strayed. It was uppermost in the minds of those who wrote the Second Amendment, with its protection of “the right of the people to keep and bear arms,” which, not incidentally, “shall not be infringed.”

That’s why Poole reminds us an “armed populace retains the last resort in preventing tyrannical leadership from consuming all power.”

You may protest: “We don’t have tyrants in America!”

Excuse yours truly for this wake-up call. It was in this land that such protection against tyrants was deemed necessary. And rightly so.

Indisputably, despots benefit by denying their subjects access to weapons. All the easier for tyrants to be tyrannical. Former Republican presidential contender Ben Carson understood that, “Through a combination of removing guns and disseminating propaganda, the Nazis were able to carry out their evil intentions with relatively little resistance,” precisely because Hitler’s thugs confiscated citizens’ guns first.

Unless progressivism has achieved its ultimate goal of fundamentally transforming human nature (suppress a chuckle here), people today are just as prone to the totalitarian impulse that prompted red coats to march to Lexington and Concord to seize colonists’ guns and ammo. What has stopped them? So far, the Second Amendment.

The authoritarian compulsion to control others creates the need to disarm those who disagree. How easy it already has become to do verbal violence by shouting down opponents. It’s a short step to putting muscle behind harsh words, like those of Cook County, Ill., State’s Attorney Anita Alvarez, who proclaimed, “I don’t think that anybody should be able to own guns.”

That brings us to the Third Amendment, adopted to prohibit “the forcible housing of military personnel in a citizen’s home.” Any remaining students of U.S. history will recall that, before the Second Amendment, the same tyrannical government that tried to seize citizens’ weapons had forcibly housed troops in citizens’ homes.

The Second Amendment doesn’t guarantee a right to shoot pheasant. It arms citizens against tyrants, who do things like commandeer your home. The Third Amendment explains the Second.

With appointments to the Supreme Court and a new president with a pen and phone hanging in the balance, be mindful that when politicians say your guns are better off if they have them than if you have them, something’s up. And it’s not something good.

So far, the Second Amendment is protected. But Hillary Clinton isn’t shy about her intention: “The Supreme Court is wrong on the Second Amendment. And I am going to make that case every chance I get.”

Think Lexington and Concord.