The Obama administration wants public school officials to rethink how they discipline and punish students who misbehave. In the mid-1990s, states put in place harsh "zero-tolerance" policies in response to a rise in violence, bullying, drug use and school shootings. But studies show that too often kids are being punished just as harshly for minor offenses. Black, Latino and disabled students are disproportionately affected. Now the departments of Education and Justice are issuing new guidelines to help schools re-evaluate their disciplinary policies.