You do understand that more people voted for Mitt Romney than Trump, right?
You do understand that the electoral college (via winner-take-all structures within states) favors the underdog because winning a state amplifies mathematically the votes within the state? (but similarly to another response to you, please please please try to argue against math.)
You do understand that the chances of him winning an already close election without the above system is unlikely right?
Yes, he won the primaries against the odds. Yes, he won the electoral college against the odds. The odds against him winning the popular vote were much longer than the others.