You just don't get it.
Trump is the first guy we've ever had who not only fights back with the media: HE WINS!
If you're so sure the media can destroy Trump, what are they going to do to Cruz?
The media has already done due diligence on Cruz and they have already shot their stuff. There is nothing left to get him on. Plus he had bonafide great grades in college and his senior thesis is not in hiding.
Trump on the other hand has got a lot of stuff that media has been seemingly ignoring. Trump thinks that the media will play nice. The media never plays nice when there is the distinct possibility that they might score yuge during sweeps.
You think he will have enough time to pay them all off?