Why the president of a group opposing the Iran deal quit

Gary Samore helped establish the advocacy group United Against a Nuclear Iran in 2008, before serious negotiations began over the nation's nuclear program. When the nuclear deal was signed last month, the group offered a near-unanimous opposition to the pact. But Samore disagreed; satisfied with the agreement, he stepped down as the group's president. He joins Hari Sreenivasan for a conversation.