He did lose the popular vote, and I'm definitely not a Trump apologist. But however you want to carve it, over 60 million people got out there on election day(-ish) and spent effort to vote for him in a non-compulsory election.
I'm first in line to criticise the primitive Electoral College, the cancerous state of US gerrymandering, and the vapidity of the two-party tribal system, but voter turnout was high. Bush and Gore each got 50M votes in the 2000 election. Obama/McCain was 70M/60M (also: McCain's loss was much greater than Trump's). Clinton/Trump was 65M/62M. Unless Trump's numbers were rapaciously Russian-ified, he still put in a solid showing with voluntary voters.
Trump's appeal was his unorthodox, un-polished dog-whistle politics, and his faithful lapped up his 'tell-it-like-it-is' approach, even if the 'like-it-is' part was fabricated out of whole cloth.