A congressman was seated next to a little girl on an airplane so he turned to her and said, "Do you want to talk? Flights go quicker if you strike up a conversation with your fellow passenger."
The little girl, who had just started to read her book, replied to the total stranger, "What would you want to talk about?"
"Oh, I don't know," said the congressman. "How about global warming, universal health care, or stimulus packages?" as he smiled smugly.
"OK," she said. "Those could be interesting topics but let me ask you a question first. A horse, a cow, and a deer all eat the same stuff - grass. Yet a deer excretes little pellets, while a cow turns out a flat patty, but a horse produces clumps. Why do you suppose that is?"
The legislator, visibly surprised by the little girl's intelligence, thinks about it and says, "Hmmm, I have no idea."
To which the little girl replies, "Do you really feel qualified to discuss global warming, universal health care, or the economy, when you don't know ****?"
And then she went back to reading her book.

Good one