It's the same as the working classes voting for brexit in the UK. Who do you think will feel the effects of the knock to the Uk economy most? It wont be the "liberal elite" anyways. Likewise with trumps support - anyone who think trump cares one jot about the working classes is delusional, he is looking after number one and that's it. Wait for his tax reform, you can bet the super wealthy will make off like bandits in his proposals.
Trump has his core, the hardcore will never be swayed, all news is MSM lies etc. but the average republican apparently is starting to have second thoughts.