Cruz is being used by the GOPe. Once he keeps Trump from the nomination they will turn on him and put someone else in, maybe even Paul Ryan.
That, and the fact that he was born in Canada. Hillary will take him apart over that.
If Cruz really believed his stick, he would drop out and support Trump.
There are only two sides, Trump and the anti Trump. Perhaps Cruz is a means to an end, but he is far and away the best candidate to upset the GOPe. Trump is a “deal maker” and will produce unprincipled results. I don’t hate the guy, I just think that he is an unprincipled, pragmatic type who in the long run, “loves” the country less than he loves himself.