Arrogance and the media. Anyone listening to the MSM in the US or abroad was told for months that Hillary was heading for a landslide. Anyone that wasn't completely partisan could see that the media was too heavy on anti Trump rhetoric to the point of making shit up, while treating Clinton like an angel. People aren't stupid. The fake polling and fake news of Hillary's certain victory caused anyone not behind Hillary to show up to vote, and a lot of die hard Hillary fans didn't think their vote was needed so they stayed home. Both the Dems and the media are so used to being above everything that they lost total touch with the masses and it bit them in the ass. They thought money could buy everything and they thought they owned our opinions. They still can't face up to their failure. Watching the snowflake media melt on election night was one of the high points of 2016 for me, and I'm not even American.