Well its a good thing no famous or political person has ever been on trial then because obviously no jury on earth could handle that fairly if it ever were to happen. I think voir dire exists mainly to make sure that folks who think like that never make it on to juries. Just because some people couldn’t render an impartial verdict on a politician they had an opinion of doesn’t make it impossible for lawyers and judges to find a jury capable of doing so. People like that exist, and lawyers find them for trials all the time, I promise you.