He's obviously posturing for future political ambitions. If Trump loses in November, Cruz can say, I stood my ground. If Trump wins and his presidency results in inevitable disaster, Cruz will look like a principled sage.
The party Establishment, so desperate to forge unity in order to generate poll numbers in November was no doubt livid.
It was a clever move but it took a degree of boldness, if not megalomania. He's obviously subject to the latter, exhibiting the typical sociopathy that afflicts most politicians. It also takes some guts to stand up and lie like that... does he really believe everything he said?
I don't know what is more frightening.... if he does, or doesn't.
Of course Trump who is more cunning than intelligent must have sensed that Cruz would posture, so he showed up and stole the crowd's attention.
It's like a car accident; you can't help but look even if it is revolting and inhumane.