Mr. Beschloss and Ms. Thomas spoke on the 1968 presidential election during the first part of a retrospective of the year 1968. The guests discussed the Democratic presidential race, which included, at different times in the year, Senator Robert Kennedy, Senator Eugene McCarthy, Vice President Hubert Humphrey and others, as well as the race between Nelson Rockefeller and former Vice President Richard Nixon. Ms. Thomas spoke via video link from the lawn of the White House.