President Lyndon Johnson signs the Tonkin resolution, which gave him power to escalate the Vietnam war. It was easily passed by both houses of Congress, although it was later repealed. MPI/Getty Images hide caption

itoggle caption MPI/Getty Images

Lou Dobbs, shown in 2007, announced Wednesday that he is leaving CNN. Karen Bleier/AFP/Getty Images hide caption

itoggle caption Karen Bleier/AFP/Getty Images