He got there because:
1. Americans were fed up with both parties being run by economic elites who cared little for the average person.
2. The Democrats fixed the election for Hillary - a corrupt elite. Her competition was a Socialist but who honestly seems to care about people. You can disagree and run around with hair on fire about socialism. If he was the candidate, he probably would have beat Trump.
3. The Republican field was rich, elites and some of the usual conservative social cause type (gays, abortion). They had little interest in the average not wealthy folks in terms of doing anything for them.
4. Trump seemed to offer, now that Hillary was candidate, someone who would care about the average folks. That got him enough votes to overcome his repellent qualities to many people.
5. Hillary's repellent qualities and the primary fix caused her constituency to stay home or go third party. I've read that the Stein vote, if pure Democratic, would have taken out Trump.
6. Hillary was bedazzled by a bunch of analytic statistical nerds who saw no need to campaign in fly over states. She ignored standard politicians who saw that the coronation wasn't going to be easy to accomplish.
7. She lost the critical ones by only 77K votes, having decisively winning the popular vote. An electoral college quirk and NOT really being a mandate, landside in human terms for Trump.
8. Russians meddled but their influence wasn't a determinant, the blather of both candidates was enough for the voters. Yes, true believers went for fake conspiracy sites but they were in the bag for their chosen sleaze bag anyway.
True believers are immune to evidence that their chosen political savior is a sleaze bag and embarrass themselves with praise of the leader. Honest folks say - Yes, the person is a sleaze bag but he or she will support some policy I like. The latter is morally suspect but understandable. The former is pathological.