Answer:
Well it all depends on which kind of advertisement you are implying. In my opinion it all started when television broadcast began to be used for political agendas. During the Johnson vs. Goldwater election, the first ever political commercial by the Johnson committee pictured a little girl counting as she picked petals off of a daisy, then suddenly a countdown begins and a nuclear bomb explodes followed by Johnson's voice, "Vote for Johnson. You can't afford not to." Ever since the first run of this spine tingling commercial, the political game changed forever.