The primaries tell his strength in his own party. He didn’t win Miami-Dade.
In 2012 there were about 8.4 million who voted in Florida.
In the 2016 primaries:
Trump had about 1.1 million
Clinton had about 1.1 million
Rubio had about 650k
Sanders had about 550k.
IOW, about 5 million voters were not heard from in the primary elections.
Okay... whatever you say...