In a personal reflection he recorded for himself, most likely in 1960, Kennedy recounted why he entered politics after finding himself, in his words, "at loose ends at the end of the war" and considering a career in business.
He said he didn't even think about going into politics until legendary Boston pol James Michael Curley left his congressional seat to serve as mayor, leaving the seat once held by JFK's grandfather vacant.
"Suddenly, the time, the occasion, and I all met," Kennedy said. "I've been running ever since. Fascination began to grip me and I realized how satisfactory a profession the political career could be. I saw how ideally politics filled the Greek definition of happiness: 'Full use of your powers along lines of excellence in a life affording scope.'"
While in the White House, though, Kennedy is seen placing an eager eye on 1964. In August 1962, Kennedy asked Gen. Douglas MacArthur, then 82, of his opinion of Michigan Gov. George Romney, the father of future Republican nominee Mitt Romney.
"Do you know this fellow Romney? Have you met Romney? George Romney?" the president asked the general.
MacArthur said he knew Romney "only casually" but added that "he doesn't stand a chance" of being elected president because he was "practically unknown" at the time. MacArthur said he had just asked 100 people he'd "happened to meet" whether they knew Romney and "there were only two knew who Romney was."
"He's a very presentable man, personally, he would fit the bill. He looks it and everything," MacArthur said. "Even if he got the nomination, he couldn't win it. And he'd have to build himself up as the governor of Michigan and make a campaign from the bottom up."
While Kennedy was beginning active plans for his re-election race, including planning for the 1964 election, he expressed concern about his political prospects. The civil rights movement was pushing Southern voters into the Republican Party, he feared, and congressional paralysis was reflecting poorly on the Democratic Party.
"Politically, the news is somewhat disturbing, looking toward 1964," Kennedy recorded in a private dictation Nov. 12, 1963 -- 10 days before his assassination. "All these make the situation politically not as good as it might be."
For Caroline Kennedy, this final recording is an emotional one.
"I think, obviously, he probably would have won and people seem to think he would have won. And my mother talks about how he was also excited about his re-election prospects and all the things he could do in a second term," she said. "But I really thought that was incredibly moving, as well, because it shows that he ... understood how difficult all of this really was."