Doris Kearns Goodwin: Would life be different if JFK was alive for his 90th birthday?

Doris Kearns Goodwin was interviewed by Brian Williams on NBC News tonight about JFK. She was asked to consider: "Would life be different if JFK was alive for his 90th birthday?" She answered it would be. She said it was possible that he would not have plunged into Vietnam in the same way as LBJ--"and that would have changed everything."