You all could be right about Trump's method and we all agree about his wanting to win and currently Cruz is his only competition.
I don't know if he's been lying about Ted Cruz or not, haven't heard what you've heard him say.
However, we don't agree about Ted Cruz not having a natural born citizen problem; he'll always have a natural born citizen problem if that's what he wants or claims to be!
So naturally, we don't agree about how big the problem might be nor about what it says about him and why nor how potentially terminal for him and his career it is to now be in this current role.
For me, it's better to just give him and Trump the benefit of doubt and entertaining to speculate about whatever the truth may be, since, even best case, we'll still just have to wait and see.
From here, what Trump is doing could easily be seen as a timely rescue attempt while sealing the deal at the same time, and then called as a win for everyone involved.
“I don’t know if he’s been lying about Ted Cruz or not, haven’t heard what you’ve heard him say.” GBA
“From what I understand everything is fine. I hear that it [Cruz’s eligibility] was checked out by every attorney, in every which way, and I understand that Ted is in fine shape.”
Donald Trump, on videotape, September 2015
http://therightscoop.com/heres-the-video-of-trump-saying-in-september-tedcruz-was-perfectly-eligible-to-run-for-president/
Trump’s recent behavior is a serious disappointment that makes me sad.