The death of Trayvon Martin has ignited debate not just over our justice system, but on legislation such as the "stand your ground" laws that contributed to the tragic result. On the next Moyers & Company (check local listings), Bill talks with author and gun control advocate Tom Diaz about how a lethal combination of self-defense laws and concealed carry laws -- championed by the NRA and the gun industry -- dilutes our legal protections against gun violence. He warns that the genie is out of the bottle and we should be gravely concerned about the unrelenting marketing of guns. Diaz's latest book is The Last Gun: How Changes in the Gun Industry Are Killing Americans and What It Will Take to Stop It. Also on the show, a hard look at the plight of the men and women who bend to the earth in backbreaking labor, picking fruits, vegetables, and tobacco. Despite miracles of agricultural progress and innovation over the decades, the harsh lives and working conditions of migrant laborers have changed very little. Their cause has been championed in the past by Edward Murrow, Cesar Chavez, and the United Farmworkers, but that list is incomplete without Baldemar Velasquez. Velasquez was among hundreds of thousands of children who joined their migrant parents working long hours in the fields. Inspired by that early experience, Velasquez founded the Farm Labor Organizing Committee (FLOC) in 1967. A 1989 MacArthur Fellow, Velasquez joins Bill to talk about the ongoing David vs. Goliath struggles to ensure fairness for American farmworkers.