Ten years have passed since the massacre at Columbine High School, said Erika Stutzman in the Boulder, Colo., Daily Camera, and, out of respect for the dead, we should renew our commitment to “uncover the mysteries” of how such tragedies can happen. “As the massacres at Virginia Tech and in Binghamton prove, it is still too easy for mentally ill people to acquire weapons to commit mass murder.”

One thing that certainly doesn’t help, said E.J. Dionne in The Washington Post, is that “the American gun lobby is just too strong” for any “rational and limited gun regulation” to get through Congress. Let’s hope President Obama can make something happen. Obama should remember that the gun lobby rallied supporters against him, and that he will “stand up for the people who actually voted for him.”

Columbine killers Eric Harris and Dylan Klebold didn’t set out to be school shooters, said Robert VerBruggen in the National Review. “They were first and foremost school bombers.” The only reason we remember them for what they did with their guns is that their propane-tank bombs—which would have killed hundreds—didn’t go off.