Actually, advertisers can't pay for adverts on anything vaguely political or controversial on YouTube full stop. Google won't let them, because the headlines in the press about <big brand> funding <terrifying-sounding characterisation of some obscure video> have cost them probably somewhere in the ballpark of a billion dollars as advertisers get scared and pull ads from YouTube as a whole. It's probably only a matter of time before the press figure out how to frame this in a way that forces them to pull the videos altogether.