With a Latino congressman’s endorsement, a boy’s heart-rending story and the mellifluous sounds of a mariachi band, Bernie Sanders began a push to woo Hispanic voters at a rally in Arizona on Friday night. As well as immigration reform, the Democratic presidential hopeful touched on gun control in the wake of last week’s massacre in Oregon and two more fatal shootings on Friday on university campuses in Houston and northern Arizona. Despite his history of opposing gun regulation, Sanders called for stronger background checks and an end to the easy availability of assault weapons. “We are tired of condolences and we are tired of just prayers. We are tired and we are embarrassed in picking up the paper or turning on the TV and seeing children in elementary schools slaughtered and young people on college campuses shot,” he said.