This more of a pet-peeve that I'm sure many of you share about politicians. I have noticed, though, that this tactic is being used more and more in debates and standard conversation. Its really sad.
People ask questions because they don't know something. The politician "answers" the question by telling the questioner something they already know and believe to be true- nothing new regarding their question, though.
The reason this normally works on people is that the politician provided intelligent reasons for believing what the questioner already knows. People's attention (when asking a question) is attracted to any new information, regardless of the relevance. The more evidence that is provided to support the new information, the more likely they are to accept it as an answer, once again regardless of the relevance to the question. But the politician has not provided any new information regarding the original question.
This is why politicians can "give answers" but not really give answers. Politicians also have perfected this art of rhetoric by changing a few words slightly in their "answers" to make it sound like it is relevant.
People who have trained themselves to identify this manipulative rhetoric, if provided the chance, may challenge it; which places the politician in the uncomfortable position of actually answering the question. Many politicians use the same tactic in response to the challenge, because they know that these discerning people are in the minority, and of that minority, only a minority have the guts to challenge them.
If they can avoid the challenge, its not likely they will have to deal with it again, and not likely that the other "undiscerning" people even care. Many politicians allow themselves to use this tactic (even though, they know it is academically and morally dishonest) because they have convinced themselves that they have answered the question and the question needs no further investigation or attention.
The true power of this tactic comes to light when the question regards defending a position. The result: If the politician can avoid an actual answer, by "answering" the question using the tactics above, they can persuade people to their position without any valid reason for the persuasion. The ultimate goal is to persuade, which in this case, the politician is victorious. But it is an empty victory.
The true danger of this tactic comes to light when the question regards defending a position on ultimate truth. The result: If the politician can avoid an actual answer, by "answering" the question using the tactics above, they have only convinced themselves of the position (and maybe many others) but, the ultimate truth does not change, and their eternal fate is at stake. The ultimate goal again is to persuade, but only the things that have no control over the eternal (people) have been persuaded. Truth itself still remains steadfast. This is not just an empty victory for the politician, but ultimate defeat for himself and those he persuaded.
As Christians, it is our duty to debate honestly. May no one ever catch us using this tactic- and if someone does, may they call us on it, immediately.
Also, don't allow yourself to be a victim of this tactic. If you find yourself in this situation, call the person it "with gentleness and respect" (1 Peter 3:15c).