actually, how about just ending the interview if they don't answer properly? Politicians go on the to defend their points and to advertise. If they don't answer the actual questions then the interviewer should just stop and go on to the next article...
I assume politicians would get the hint pretty quickly.
Good in principle, but you send a reporter and tv crew to interview someone using up their day and needing to produce something for the evening news, and what are they supposed to do?
It would be nice not to hear the same old tripe though.