I don’t think you are remembering things clearly. Trump admitted at one of the debates that he unloaded on Cruz because Cruz was rising in the polls. Just flat out said yeah he was rising in the polls! I don’t believe Cruz was drafting Trump he was just trying to live up to a standard Trump cares nothing about.
This all started when Cruz was meeting with his billionaire donors and telling how he was playing kissy-face with Trump and Carson, playing for the right time to stick a shiv in their backs. That's when Trump became grumpy.
Cruz is an arrogant, overtly ambitious little boy in an adult body, who believes that he is better than he really is and got his nose bent out of join t when W didn't see him that way. Cruz didn't get the job he wanted, from W, so decided to get higher jobs by any means there were.
Cruz, no matter what he may claim, is an INSIDER and a pol. Trump isn't either.