Beau Biden — the eldest son of US Vice President Joe Biden and a rising star of a political dynasty — has died after battling brain cancer. He was 46. Beau, the former attorney general of Delaware, had been admitted recently to Walter Reed National Military Medical Center in Bethesda as he fought the cancer, a battle that his father largely kept private. “The entire Biden family is saddened beyond words. We know that Beau’s spirit will live on in all of us — especially through his brave wife, Hallie, and two remarkable children, Natalie and Hunter,” Vice President Biden said in a statement released last night.