As I remember reading about . . .
Ronnie lost Iowa because his main campaign guy told him he had it in the bag, and on this guy's advice, didn't participate in a debate.
At some point in New Hampshire, a couple of campaign guys visited Ronnie late at night. And when they left, he said to Nancy, next time those bastards will be after Ed. (meaning Ed Meese)
And on one occasion, Nancy followed a couple of campaign people back into the hotel's hallway and informed them that that had been no way to talk to her husband and that was not exactly the kind of approach to motivate him.
And as I remember it, the Reagan Campaign announced a change of leadership sometime during the evening of the day of the New Hampshire primary, figuring that this announcement would be largely lost in the day's news.
A lot of interesting stuff for what people think of as a cake walk! (much of this from Germond and Witcover's book on the election)