September 11, 2001 is a day the US will never forget. In this special edition of CNN Political Briefing, CNN Political Director David Chalian reflects on how that fateful day 20 years ago changed American politics and the legacies of four Presidents in ways still felt today. Many remember exactly where they were that day–so does the host, which you’ll hear about in this episode.To learn more about how CNN protects listener privacy, visit cnn.com/privacy