The same post offered some ideas about the sources of his support at the time. I said that a large part of his appeal was negative--people distrusted politics and politicians, and he was an outsider. An alternative is that he made a positive connection to a large number of voters. Reporters who attended his rallies were often struck by the energy, and many people talked about an "enthusiasm gap" in favor of Trump during the general election campaign. A Pew survey in October 20-5, 2016 asked separate questions about whether Trump and Clinton would be: great, good, average, poor, or terrible. The results:
Great 9% 10%
Good 17% 28%
Average 15% 18%
Poor 12% 12%
Terrible 47% 31%
That's not much enthusiasm for Trump, but it includes both supporters and opponents. If we limit it to people who said they would support the candidate:
Great 21% 19%
Good 39% 54%
Average 30% 25 %
Poor 7% 2%
Terrible 2% 0%
At least in this respect, Clinton supporters were move favorable about their candidate than Trump supporters were about theirs. In fact, 10% of the people who said they would vote for Trump thought that he would be a poor or terrible president.
On a possibly related note, of the people who had the same expectations of Trump and Clinton (e. g., said both would be average), 75% said they would vote for Trump. I haven't investigated, but one possibility is that they were Republicans who figured that even if he wouldn't be especially good, Republicans in Congress would get their way if he were president. So I think my original analysis was correct on that point--Trump got the Republican nomination more because of his opponents' weakness than because of his strength. After he got the nomination, party loyalty kept him close enough to have a chance.
[Data from the Roper Center for Public Opinion Research]