former joseph ratzinger, made history today when he left the vatican in a helicopter from rome to the papal summer home, castel gandolfo, for the first phase of his retirement. in his final tweet as pope he said, quote, thank you for your love and support. may you always experience the joy that comes from putting christ at the center of your lives. his departure ushers in a new era for the church and the more than 1 billion catholics worldwide, and soon more than 100 cardinals will meet in conclave to select a new pope and decide the future of the faith. george weigel is our nbc news vatican analyst, and tom roberts is managing editor of "the national catholic reporter" and author of "the emerging catholic church." george, you know, in american presidential politics, we always try to correct for the latest president. you know, we had truman who had too much of a kansas city problem, so we brought in mr. clean eisenhower. we had nixon and ford, so we brought in a guy who had never been involved in politics or been to washington, carter. and we brought in reagan because he was seen as strong, and carter was seen as weak. what will they try to correct in