Собаку съел
Речь, понятно, идет не о собачьей шерсти, а о дозе алкоголя для опохмелки, которая и называется "Hair of the dog". Гражданин политик, нажравшись с вечера, с утренней дозой тоже перебарщил, соответственно, говорить речь с трибуны ему сложно.
"Then Willie stood up all alone by the table, saying, "My friends," and turning his alabaster face precariously from one side to the other, and fumbling in the right side pocket of his coat to fish out the speech.
While he was fumbling with the sheets, and looking down at them with a slightly bemused expression as though the stuff before him in a foreign language, somebody tugged at my sleeve. There was Sadie.
"How was it?" she asked.
"Take a look and guess," I replied.
She gave a good look up to the platform, and then asked, "How'd you do it?"
"Hair of the dog."
She looked up to the platform again. "Hair, hell," she said, "he must have swallowed the dog."
Robert Pen Warren "All the king's men".
В Urban dictionary - подробное толкование:
" An alcoholic beverage consumed as a hangover rememdy. The phrase comes from the expression "hair of the dog that bit you", meaning that the best cure for what ails you is to have some more of it. In ancient times it was literally used to say that if a dog were to bite you, putting the dog's hair into the wound would heal it. "Like cures like".