so interesting. gaga always in the news. we begin with the president's challenge at the u.n. calling on world leaders to stand up against violence and extremism. >> president obama devoted much of his speech to the arab democratic movement, free speech, and also stopping the violence like that attack in libya that claimed the lives of the u.s. ambassador and three other americans as well. here's abc's jake tapper. >> reporter: president obama made the focus of his united nation's address about a man who wasn't there. >> i would like to begin today by telling you about an american named chris stevens. >> reporter: with a tribute to the u.s. ambassador to libya who was attacked and killed in the dead of night in benghazi two weeks ago, he extolled the humanity and hope stevens stood for. >> if we are serious about these ideals, today we must reaffirm our future will be determined by people like chris stevens and not by his killers. >> reporter: but in many ways, the president's speech seemed targeted at his domestic audience. accused by republicans of glibly downplaying the unrest in the