who is author of this book, "the kennedy half century" and director of the center for politics at the university of virginia. professor, i've enjoyed reading this. it's a wonderful book. what's interesting about it, what struck me initially is that president kennedy's achievements in office were regard by some as not all that remarkable, but you conducted an extensive survey by peter heart and jeff guerin and it found kennedy to be by a wide margin, the most esteemed president since 1953. why is that? >> gregg, there is no question that a lot of it is the assassination itself. the blood from that assassination, that horrible event on elm street, the real nightmare on elm street in