It was supposed to be the night when Richard Nixon, vice president of the United States, reestablished control in the race for the White House. He would demonstrate his qualifications, prove the inexperience of his challenger and overcome the tactical mistakes that had plagued his campaign to that point. It turned out to be a mismatch. Mr. Nixon looked sweaty, pale and uncomfortable, while John F. Kennedy seemed fresh, cool and presidential on Sept. 26, 1960, when the two candidates met in Chicago for the first televised presidential debate. Seven weeks later, Mr. Kennedy was president-elect, having won one of the closest national elections in U.S. history.