In a country where assassins have gunned down four presidents and nearly killed two others, and where shooting rampages take place with such sickening regularity that many Americans no longer are shocked by the carnage, we find ourselves repeatedly asking the question: What will it take to pass effective gun-control laws?

It is understandable such legislation hadn't been passed during the Wild West era following the shootings of presidents Abraham Lincoln in 1865 and James A. Garfield in 1881, or even William McKinley in 1901.

But after the assassinations of President John F. Kennedy in 1963, and Martin Luther King Jr. and Robert F. Kennedy in 1968, why have lawmakers continued clinging irrationally to a misinterpretation of the Second Amendment? Though Congress did pass the Gun Control Act of 1968, it focused on the interstate commerce of firearms and did little to prevent handguns from getting into the wrong hands.

Lynnette "Squeaky" Fromme, a Charles Manson follower, certainly had no problem obtaining a gun that she tried to fire at President Gerald Ford in 1975 before it was wrestled away by the Secret Service. Three weeks later Sara Jane Moore, a self-styled radical, did manage to get off a shot at the president, but the bullet barely missed the president's head and wounded a cab driver.

Likewise, Jodie Foster stalker John Hinckley, who had been previously arrested on a weapons charge and received psychiatric treatment, was able to obtain a pistol he used to shoot and wound President Ronald Reagan and his press secretary, James Brady, in 1981.

Mr. Brady's name is on a bill that has sought - and largely failed - to keep criminals and mentally unstable people from owning handguns. It took 12 years to pass the Brady Handgun Violence Prevention Act that, for the first time, instituted federal background checks on firearm purchasers in the United States.

The act, though, contains loopholes. While authorities have used the Brady Law to prohibit millions of prospective gun owners from buying firearms, countless others apparently have slipped through the cracks.

Among them are Seung-Hui Cho, the Virginia Tech student who shot and killed 32 people and wounded 25 others before committing suicide in 2007. He had been diagnosed with a severe anxiety disorder and ordered to seek psychiatric treatment.

Meanwhile, colleagues of Maj. Nidal Malik Hasan, the Army psychiatrist awaiting a court martial next year on charges he shot to death 13 people and wounded 29 others at Fort Hood in Texas in 2009, often warned about his erratic and paranoid behavior.

Though his own family fretted over his mental instability, Jared Loughner evidently was considered sane enough to buy the gun that he used to shoot 20 people, including Arizona Rep. Gabrielle Giffords in January. Six people died, including a federal judge.

He now is considered mentally unfit to stand trial.

And Rodrick Shonte Dantzler, who went on a shooting rampage in Grand Rapids, Mich. in July that killed seven people and wounded two others before taking his own life, had access to a gun despite having been imprisoned for a 2000 shooting incident. He also had been convicted of domestic violence after three women filed protected orders against him.

Last month, Eduardo Sencion stormed into a Nevada IHOP and opened fire with an AK-47 on five uniformed National Guard members, killing two and another person before killing himself. His family said he had "mental issues."

And last week, Scott Dekraai used three handguns to shoot up a beauty salon in Seal Beach, Calif., killing eight people. He had been involved in a custody dispute with a former girlfriend, one of his victims.

Evidently, our laws have valued the "rights" of these gun-owners more than the lives of their victims.