The National Rifle Association rates Arizona Gov. Jan Brewer as an A+ gun supporter. This week, though, she flunked an NRA test.

Good work, governor.

The gun-rights Republican vetoed a bill that would have partially lifted the state's ban on guns at college and university campuses. The bill, altered from earlier wording that would have allowed loaded guns in classrooms, was changed to allow them only on a "public right of way." In her veto letter, the governor said that the bill was too vaguely worded and might have been interpreted to permit weapons at K-12 schools.

Across the nation, the gun lobby has been working hard to get weapons on campuses. It is pushing to lift the ban in Texas and eight other states. But this is one area where those who support reasonable restrictions on guns have had success. Since the mass shooting at Virginia Tech in 2007, guns-on-campus bills have been shot down or died in 24 states.

The NRA argues that people on campuses need guns for self defense and that the presence of guns will not lead to more violence. They point to Utah, the one state that has lifted the ban, as Exhibit A. It has not seen violence increase on campuses since the ban was removed in 2006.

The entire guns-on-campus push, however, is more about increasing gun acceptance than the need for self defense, points out Adam Winkler, in a recent New York Times op-ed. A professor and gun expert at the University of California, Los Angeles, Mr. Winkler says there are fewer than 20 homicides on campuses per year. The real issue, he adds, is getting the next generation used to having guns everywhere.

But college is a place where it will never make sense to have guns. For all of their independence, college students are still working at growing up. Federal law recognizes this by banning anyone under 21 from buying a gun from a dealer. Does America really want to mix frat parties with Glocks? And as law enforcement officers frequently point out, when a shoot-out is going on, it's not easy to tell good guys from bad guys.

Gov. Brewer seems to have stopped the campus-guns drive because of a technical concern. Let's hope that if this bill is reworded and comes to her desk again, that she will veto it simply with the understanding that guns don't belong on campus.