Slate's William Saletan points out the potential dangers that come with encouraging citizens to carry guns and fire at will in situation's like Saturday's shooting:

This is a much more dangerous picture than has generally been reported. Zamudio had released his safety and was poised to fire when he saw what he thought was the killer still holding his weapon. Zamudio had a split second to decide whether to shoot. He was sufficiently convinced of the killer's identity to shove the man into a wall. But Zamudio didn't use his gun. That's how close he came to killing an innocent man. He was, as he acknowledges, "very lucky."

That's what happens when you run with a firearm to a scene of bloody havoc. In the chaos and pressure of the moment, you can shoot the wrong person. Or, by drawing your weapon, you can become the wrong person—a hero mistaken for a second gunman by another would-be hero with a gun. Bang, you're dead. Or worse, bang bang bang bang bang: a firefight among several armed, confused, and innocent people in a crowd. It happens even among trained soldiers. Among civilians, the risk is that much greater.

Read the whole thing here.

Meanwhile, Dave Weigel looks at how the Arizona Legislature is likely to loosen gun regulations this year:

The point of all this is that there's very little gun-control activists can do in Arizona in the aftermath of the Tucson shooting. They can point out that Loughner had shown signs of mental problems before he was sold a Glock 19 at the Tucson Sportsman's Warehouse, or bullets at a local Wal-Mart. But the state prohibits any coordination of mental health records with the National Instant Criminal Background Check system.

So Arizona's response—the most likely legislative response—is going to be expanded gun rights. Heller told me on Monday that the Arizona Citizens Defense League has drafted legislation that would allow the state to train members of Congress and their staffs in firearms, and give them access to firearms they could carry in their districts.