I agree with this article but it goes deeper. Right wing media had been fueling the discontent for years. Some on the right like Mark Levin seemed to be using that in order to lay the groundwork for Cruz. Some like Breitbart News were using Cruz as their early standard bearer, their stalking horse, until Trump entered the race. The money behind all of this is Bob Mercer who backed Cruz, bankrolled Breitbart and then quickly shifted funding and resources to Trump. They used Cruz to create the environment, to set the table, and then Trump walked in, cranked the rhetorical knob to “11” and and ate the lunch seemingly prepared for Cruz. Oh, and Mercer’s co-CEO at his hedge fund is one of Clinton’s primary donors.
You will note Renaissance Technologies is (by far) Trump’s #1 overall donor. This mess was brought to you, bought and paid for, by Bob Mercer.