Downvoted because in 2016 there was a "social engineering hack" and Trump received 63 million votes. In 2020 I haven't seen much evidence of that and Donald Trump received at least 70 million votes. He's a popular guy among a very significant percentage of the population... like it or not.

Hillary lost due to being an extremely unlikable candidate. In addition, she faced a charismatic and controversial wildcard candidate who promised to shake up the system in a time where people were sick of career politicians.

And a portion of dem voters were pissed off about how Sanders was treated by the DNC, though I have no idea if that caused any meaningful portion to abstain or vote for Trump.