It hardly matters whether Michael Murphy deliberately planted Barack Obama moments in “The Conscientious Objector.” This play about the Rev. Dr. Martin Luther King Jr.’s decision to oppose the war in Vietnam is fraught with contemporary resonance, as a charismatic black man takes a stand against a white president who is stubbornly continuing an unpopular war. Marveling at the news that the recently appointed secretary of defense claims to be shocked at the lack of a war (...)