Eugene Byrne is a freelance journalist and author, and a regular contributor to BBC History Magazine. You can read his online blog at http://eugenebyrne.wordpress.com/
Every year, the Gridiron Club, an organisation of journalists in Washington DC, holds a dinner. This is a prestigious white-tie affair attended by America's political and media elite, and the entertainment always includes political speakers who are expected to make humorous or self-deprecating addresses.
In March 1958 John F Kennedy was asked to speak. Everyone knew he was a rising star; he had failed to secure the Democratic nomination for Vice President in the 1956 election, but was now being tipped as a front-runner for 1960. More immediately, he was seeking re-election to the Senate.
Addressing the dinner, Kennedy pulled a piece of paper from his suit pocket, saying it was "a telegram from my generous daddy".
He read: "Dear Jack, don't buy a single vote more than is necessary. I'll be damned if I'm going to pay for a landslide."
This episode is often quoted as an example of the political dexterity of JFK – or his advisers anyway. Kennedy in 1958 was an unknown quantity to most Americans, and those who did know anything about him weren't sure they liked what they knew.
For one thing he was a Roman Catholic, and for another plenty of people knew his father, an immensely wealthy businessman with a lot of political connections and a reputation as a backstairs operator. By making a crack about his father at the annual beano of the Washington press corps JFK went a long way towards defusing the family wealth, and his controversial father, as a political issue.
Neither this gag, nor the rest of the speech were in any way spontaneous. Ted Sorensen, JFK's most influential speechwriter, later wrote that he had spent hours rehearsing it beforehand. Sorensen was also long suspected of penning the famous: "Ask not what your country can do for you but what you can do for your country" line which Kennedy used in his inaugural address. Whenever quizzed on this, Sorensen's reply was always: "Ask not."
Even without speechwriters, Kennedy was relaxed and witty in public, with a nice line in self-deprecating humour. When asked by a small boy how he had become a war hero (he had been decorated for service in motor torpedo boats in the Pacific) Kennedy replied: "It was absolutely involuntary. They sank my boat."
Other presidents were more dependent on their writers. Gerald Ford (President 1974-77) often used the services of one-liner maestro Robert Orben, who became frustrated that the clumsy Ford often fluffed some of his best lines. Orben wrote out a card which he pasted into Ford's speech binder saying: "I told my wife I knew this speech backwards, and that's how I'm delivering it."
The line always got such a good laugh that Ford now started deliberately mangling his speeches just so he could use it.