I really don’t see Kasich hurting Trump. Trump supporters have the fervor of whirling dervishes, and KAsich isn’t going to take their vote. I see Kasich and Rubio staying in to split the non trump vote and deny Cruz the nomination. After all, the GOPee can make deals with Trump, and Cruz would stonewall them.
Um, Rubes is out.
As for Cruz stonewalling the GOPe, that's an extremely tough sell given the events of just the last week.