I live in the rural South and although it may sound ridiculous to you, I've met more people here that believe all of the inflammatory, fake nonsense they read on FB than I have that don't. They use it as a primary source of news and they allow it to shape their view of the world and therefore their beliefs on certain political policies. While it's difficult to quantify with a specific percentage, there were absolutely a large number of people tricked, in the literal sense, into voting for Trump. These are the people that are Ill informed enough to think that women are certain to get raped by a pack of muslims if they ever try walking down a street anywhere in Europe.
Note: Surely this doesn't account for everyone that voted for Trump, but it is possible that it made enough of an impact to change the outcome.