The slaughter of innocents in Newtown, Conn., 15 days ago has prompted renewed debate about how to minimize the risk of such barbarism. It also triggered familiar calls for tougher gun laws.

Even if that heart-wrenching atrocity had never occurred, millions of Americans reasonably concluded long ago that the right to bear arms shouldn’t include the right to bear semi-automatic firearms with 30-, 50- and even 100-round magazines.

Nor should that Second Amendment “right to keep and bear arms” preclude practical regulations requiring background checks for gun owners.

Those common-sense viewpoints appear to be gaining overdue ground in the wake of the Newtown carnage.

A USA Today/Gallup poll released Thursday found that 58 percent of respondents favor strengthening laws covering firearm sales — up from 43 percent last year.

Some of that increase stems from the lingering horror over the massacre of 20 children and six adults at Sandy Hook Elementary School in Newtown.

But that abomination isn’t the only recent example of American gun mayhem run heinously amok. Five months ago, a lone gunman whose arsenal included a semi-automatic rifle with a 100-round magazine killed 12 in a movie theater in Aurora, Colo.

In early 2011, a lone gunman bearing a semi-automatic pistol with a 100-round magazine killed six people (including U.S. District Judge John Roll and 9-year-old Christina Taylor Green) and wounded 13 more, including Congresswoman Gabrielle Giffords, at a shopping center in Tucson, Ariz.

And five days ago, on Christmas Eve, (after the Gallup poll was conducted), a lone gunman whose weapons included an AR-15 with a 30-round magazine killed three firemen who were responding to a house blaze in Webster, N.Y.

The lone gunman in Newtown also used an AR-15.

Those are among the reasons many Americans, including President Barack Obama, are calling for a reinstatement of the “assault weapons ban.”

That law, passed by Congress and signed by President Bill Clinton in 1994, had a 10-year limit — and Congress declined to renew it in 2004.

By then, the gun lobby, led by the National Rifle Association, had flexed intimidating political muscle in elections after the initial assault-weapons ban.

Indeed, 2004 Democratic presidential nominee John Kerry, mindful that Al Gore’s support of tighter gun control had cost him dearly in the 2000 election, decided that a-hunting he would go while plenty of cameras were around to shoot images of him shooting ducks.

President Obama also has been reluctant to rile the NRA — until last week.

Closer to home, state Sen. Lee Bright, R-Spartanburg, has prefiled a ludicrous bill to exempt South Carolina from federal gun regulations — as if any judge would deem that a state’s right.

And the NRA, after observing a week of silence following the Newtown nightmare, has been firing back against calls for more severe restrictions on firearms. Along with other gun-rights groups and some right-wing radio stars, the NRA cites a raft of statistics to support its case.

Yet the NRA can’t erase the aforementioned statistics of 26 fatal victims, including 20 children, in that Connecticut school.

Other chilling stats: That killer fired from three to 11 rounds into each of those students — and the 12 little girls and eight little boys he murdered were either 6 or 7 years old.

Certainly there are numerous other factors behind mass shootings in modern America. Among the likely suspects are a breakdown of the mental health care system and the glorification of violence in our entertainment culture and video games.

No, tougher firearms laws wouldn’t eliminate deadly shooting sprees in a nation where there are already more than 250 million guns.

And yes, Americans do have a constitutional right to keep and bear arms — and to use them to protect their families, homes and businesses.

But here’s a question for the self-proclaimed “conservatives” still echoing the NRA’s talking points:

What’s so conservative about easy legal access to semi-automatic weapons that are being habitually used for mass murder in public places?