Well, for one, Breitbart is partisan/ideological news, not fake news. You could ask the same question of left-leaning sources (NYT, WaPo, Huffington, many more)

Well, for one, Breitbart is partisan/ideological news, not fake news. You could ask the same question of left-leaning sources (NYT, WaPo, Huffington, many more) that support Democratic candidates before an election. Obviously most news outlets will try to influence elections in some way, if they have an editorial stance. And sure, sometimes they may have enough influence to actually shift an election. But "fake news" like "FBI agent murdered by Hillary" or Pizzagate nonsense is a blip on the radar compared to all of the other news sources out there. Those hoax stories probably did not tip the US election at all.