Kathleen Hall Jamieson of the Annenberg School for Communication says public opinion is not easily changed with one speech.<br><br><a href='http://www.usatoday.com/news/washington/2007-01-08-bush-speech_x.htm' target='_blank'>http://www.usatoday.com/news/washington/2007-01-08-bush-speech_x.htm</a><br><br>