Whenever pressed with a serious question, the interviewee always falls back on the habit of feigning attempt at a reply then we watch as they, halfway through the answer, trail off onto a dead end, long blink, then, "Look. The fact of the matter is......" They then follow with a digression into Irrelevant Land thereby moving the entire discussion.
Watch them......McCain, his old lady, Rudy "The squirrel", the whole gang. Anything they wish to just duck, is handled with this poor tactic. Dig.