Trump has pretty much left Bernie alone but if needed a case to demolish his nutty ideas, Trump need only focus on how Venezuela is a real life case study of Bernie’s economic ideology.
My Venezuelan friends emigrated around 15 years ago. V. once had a flourishing prosperous great economy.
Bernie supporters have their heart in the right place, but they need an education on the reality of governmental systems. A movie would do the trick and wake the majority. They have no idea what they are getting themselves into with socialism/communism.
Bernie is not a threat to Trump. Trump so far has been playing it well, pointing out democrat corruption, but treating democrats themselves with respect, especially Bernie supporters. After Bernie loses many will be able to consider Trump, and Trump is willing to compete for him.