Whenever some troubled person massacres innocent people, we struggle to understand why. It's a largely futile exercise. Unstable people do crazy things for inexplicable reasons.

Jared Loughner opened fire Saturday at a political event outside a supermarket in Tucson, police said, killing six and wounding 13, including Rep. Gabrielle Giffords (D-Ariz.). The barrel of his Glock semiautomatic was barely cold before a narrative emerged laying blame for the rampage on overheated partisan rhetoric that casts political opponents as enemies of the nation. That prospect is troubling. But whether Loughner's choice of targets was influenced by that kind of political demonization isn't yet known.

Whatever his motive, it would be good if elected officials, the media and the public turned down the heat in our political discourse. That includes those who use symbolism like rivals in the crosshairs, or talk recklessly about a Second Amendment solution to political disputes. It also includes those who would exploit this tragedy by reflexively blaming political opponents for inciting Loughner. Vilifying one another won't stop the violence or solve the nation's problems.

Court documents, Internet ramblings and high school friends portray Loughner as a troubled, anti-government loner. Bizarre outbursts and non sequiturs led some to suspect mental problems that could make him dangerous, prompting his ouster from community college. Officials said he bought the Glock handgun in November and plotted to kill Giffords.

The gun was recovered with clips that held about 30 bullets, allowing him to fire that many times before pausing to reload. One thing is clear: No civilian needs access to 30-bullet clips. Such high-capacity, semiautomatic-weapon magazines were illegal nationally for 10 years before Congress allowed the ban on assault weapons to expire in 2004. The clips are still illegal in New York, and Rep. Carolyn McCarthy (D-Mineola) said she will introduce legislation this week to reimpose the national ban.

Gun control of any sort is a tough sell in Congress these days, but that commonsense restriction should be enacted. Such large-capacity clips play an obvious role in turning angry outbreaks of violence into massacres.

With a federal judge among the dead and Giffords fighting for her life, other public officials have reason to worry about their own safety. Security will no doubt be enhanced. And there's a reasonable impulse to limit public contact in events like the "Congress on Your Corner" that Giffords hosted. That would be unfortunate. Democracy works best when the public and its representatives interact freely.

Understanding homicidal madness may be impossible. Maybe the best we can do is to try to head off such violence, and when we can't, persevere in the face of tragedy. hN