I have just finished Robert Harris' Imperium - a fantastic historical-fiction account of the life of Cicero. At one point Harris describes the process of speech-writing and it reminded me of sermon-writing:
No one can really claim to know politics properly until he has stayed up all night, writing a speech for delivery the following day. While the world sleeps, the orator paces around by lamplight, wondering what madness ever brought him to this occupation in the first place. Arguments are prepared and discarded. Versions of openings and middle sections and perorations lie in drifts across the floor. The exhausted mind ceases to have any coherent grip upon the purpose of the enterprise, so that often - usually an hour or two after midnight - there comes a point where failing to turn up, feigning illness and hiding at home seem the only realistic options. And then, somehow, under pressure of panic, just as humiliation beckons, the parts cohere, and there it is: a speech. A second-rate orator now retires gratefully to bed. A Cicero stays up and commits it to memory.