As a Cruz supporter I will try to answer what went wrong. Cruz appeal was to the “intellectual” conservative. He is (was) a candidate that we have been told could never win the primary. This year likely would have been different absent Trump’s entry into the race.
His first mistake was not supporting Trump against the riot in Chicago. He still had a chance at that time. I even winced at that. He also lost the PR battle over the intricate delegate selection rules. Trump was a master marketer on the big things.
I am in the #NeverHillary camp so I am more than willing to gamble on Trump. I hope he surrounds himself with some true small government conservatives but only time will tell.
Trump will not say it until his nomination is officially secure but I believe he will eventually show great respect for the battle Cruz waged. Not the missteps but the organizational approach. After all Trump slayed them all and only Cruz gave him any real fight.
Yeah, the rally/riot thing didn't help, either.
We don't even think about it now, but Trump went after Jeb Bush HARD right out of the gate. He recognized that Jeb Bush's money and connections would be very hard to beat if he got any traction with the voters.
Cruz thought Trump would be a passing fancy, and he was "allied" with Trump... with the plan to gather up Trump's support when the inevitable collapse happened.