The establishment is terrified
Did you hear Mark Steyn on Rush today? He quoted an article by Mark Kirkorian (who I don't think is pro-Trump) but anyway if I remember this right he said Ted Crus is the "anti-establishment" candidate, but Trump is the "anti-regime" candidate. One is seeking to change the leadership at the top of the club, the other is threatening to throw everyone out of the club and start over.
You are right. The establishment is scared. They are scared because Hillary WILL be President if Trump is the nominee.