On the evening of Aug. 8, 1968, Richard Nixon delivered his acceptance speech for the Republican nomination, which he had won the same day. James Reston of The Times called it “the greatest comeback since Lazarus.”

For many Americans long accustomed to seeing Mr. Nixon lose, it was disorienting to see him on the rostrum so … victorious. The old scowl was gone, the hair was a little longer and, as his handlers promised, a “New Nixon” beamed reassuringly for the cameras. 

Yet it was a strange speech, alternating between genuine grace notes and darker rumblings from an American subconscious that was sullen and fearful after years of war and discord. Like tectonic plates grinding against each other, the tensions between these visions, alternatingly bright and horrific, would be difficult to resolve. 

Eight years earlier, Mr. Nixon had been a famously awkward candidate who tried much too hard, sweating it out to make it to all 50 states in 1960, while John F. Kennedy casually threw spiraling footballs for the photographers of Life and Look. But a lot had changed since then. Mr. Nixon’s handlers, especially the younger ones, included a new breed of TV executive, who understood that Mr. Nixon could reinvent himself with softer lighting, better angles and fewer appearances. That, in essence, was the New Nixon. They devised a savvy strategy, outlined by one of their own, Joe McGinnis, in his classic book “The Selling of the President, 1968.” Thanks to their tutelage, he now seemed a calmer kind of statesman who spoke gnomically once a day, with plenty of time to get the footage to the networks. The spread of color TV between 1960 and 1968 helped Mr. Nixon, too; it eliminated the ghostly pallor and 5 o’clock shadow that had terrified schoolchildren in 1960. Air conditioning, another miracle, reduced the pools of perspiration that glistened when the lights burned too brightly. 

Florida had already been good to Mr. Nixon, before the Republicans came to Miami. As Dwight D. Eisenhower’s running mate in 1952, he had pleaded poverty as evidence of good character during his famous “Checkers” speech. But in the intervening years, he had quietly amassed a fortune in Miami real estate, thanks to his close friend Bebe Rebozo, a well-connected Cuban-American. If Mr. Nixon seemed more confident, it may have had something to do with these properties, which made up almost half of his sizable wealth in 1968. His comeback had begun in Miami, in 1962, when he began to buy up parcels after losing the California governor’s race. ...