Many questions are stupid. Many are irrelevant. Many make presumptions of the questioner which the candidate may or may not accept.
The test is not whether the candidate can answer the stupid question. The test is whether the candidate can control the situation ... or does he let the situation control him?
Which type of person do you want as president?
Yes! Bring a Cruz supporter a moment that sticks in my minds was when he recited a litany of the stupid questions that had been asked every other candidate.
Here's an idea of some basic unfairness I might have heard.
Asks Candidate A: "Mr. A, Mr, B has called Mr C's policy on Iran dangerous and unworkable. Do you agree?"
I don't have any examples, but I would not be surprised if Trump had been on the dirty end of that stick.