I often hear it stated as "We disliked Hillary so much, we voted for someone worse".
But the more accurate statement is that some groups of people decided not to vote at all because they disliked Hillary, and other groups of people decided to show up and vote.
You are forgetting that most Americans are self-proclaimed independents and not sworn to support either of the two parties.
https://news.gallup.com/poll/15370/party-affiliation.aspx
If you look at the week by week numbers, you see variance; I suspect most independents lean one way or another, but their willingness to commit in a poll varies based on various affairs.