Sure, you can say that Brexit are incredibly populist and play on peoples fears, but... the Bremain side was no better. Essentially, my take on it was, that the Brexit side was targeting the incredibly stupid people with fears like immigration, whereas the Bremain was targeting the merely stupid people with fears like economy crash. Neither seemed to have any kind of justification to their main arguments, or any other sensible argument.
The situation in the US seems very similar. Sure, Trump is spewing inconsistent nonsense left and right, but Hillary has nothing to say, period. Part of me thinks that she's so embroiled in potential scandals that it's actually better for her to say nothing, and hope that Trump auto-ignites and explodes based on his speech...