Only a little under 25% of the US affirmatively voted for him in the 2016 election (a little over 25% voted for his opponent, and roughly 50% chose to not vote at all). Included in that 25% would be people who either voted against his opponent, or voted on a single issue that overrode all other considerations (in the US, blocking legal abortions is the single biggest driver of these voters).
If people chose not to vote, I don't think their opinion matters too much. Excluding people ineligible to vote and people who didn't vote out of protest, although a better choice would have been to write in a vote.
