The U.S. Supreme Court on Tuesday gave America a gift in the fight against senseless gun violence: On this day our high court justices did not take the side of the gun industry and the National Rifle Association.

Instead justices declined to review the Remington Arms Co. appeal which sought to stop the families of victims in the 2012 Sandy Hook school massacre from proceeding with their lawsuit against the maker of the Bushmaster AR-15-style rifle, the gun used to kill 20 first-graders and six elementary school staff members.

Neither the court's move nor the lawsuit is about the Constitution's Second Amendment right to keep and bear arms.

Rather, the issue before the court was about gun marketing and liability. It was — and continues to be — about common sense law and morality vs. the almighty dollar.

With no comment, the justices turned away Remington's appeal of a earlier ruling by the Connecticut Supreme Court which had let the lawsuit proceed despite a 2005 federal law known as the Protection of Lawful Commerce in Arms Act. The 2005 measure was passed by an NRA-cowed Congress aiming to block a wave of lawsuits damaging to the firearms industry as mass shootings began to mount in America.

(Read more: Supreme Court lets Sandy Hook lawsuit go forward)

The Sandy Hook suit contends that Remington bears some of the blame for the tragedy because the Bushmaster — a semi-automatic civilian version of the U.S. military's M-16 — is a knock-off weapon of war "knowingly marketed and promoted" to civilians "for use in assaults against human beings." That marketing, the suit contends, violates an exception in Connecticut's consumer protection law which forbids advertising that promotes violent, criminal behavior.

Remington's ads, despite consumer laws "continue to exploit the fantasy of an all-conquering lone gunman." One ad, the suit notes, stated, "Forces of opposition, bow down."

Gun violence and AR-15-style rifles * Since 1999, there have been 115 mass shootings in America, killing 941 people and injuring 1,431. * A quarter of them involved semi-automatic rifles and accounted for 40% of all deaths and 69% of all injuries. * Since 2017, 12 of the 31 mass shootings involved assault rifles. Source: Axios, using mass shooting data collected by Mother Jones

Remington, on the other hand, says the case "presents a nationally important question" about U.S. gun laws — namely, how to interpret that 2005 federal law that grants broad immunity to gun-makers and dealers.

The NRA got its 2 cents worth in, as well, telling justices in a filing that the lawsuit could put gun manufacturers out of business, making gun rights meaningless. The NRA, along with 10 mainly Republican-led states and 22 Republicans in Congress, had urged the high court to jump into the case and end the lawsuit against Remington. Those states included Alabama, Georgia and Arkansas.

One of the plaintiffs in the case is David Wheeler, whose 6-year-old son, Ben, was killed in the Sandy Hook shooting. Wheeler told National Public Radio earlier this year that to him, the lawsuit is about responsibility. And he recalled one of Remington's ads for a gun that carried the tagline, "Consider your man card reissued."

"What kind of society allows manhood to be defined in this way?" Wheeler asked.

Indeed.

By the way, Remington, which last year emerged from bankruptcy with less debt, for a time flirted with relocating to Tennessee where our Volunteer State lawmakers in 2016 voted the Barrett .50 caliber rifle the state's "official state rifle."

The Barrett .50 caliber rifle, which is manufactured in Tennessee at the Barrett Firearms Manufacturing Co. in Christiana, is another military weapon that can "penetrate light armor, down helicopters, destroy commercial aircraft, and blast through rail cars."

And, yes, it's also legally available to civilians.