There is no guarantee all, or even most, Kasich votes will got for Ted Cruz. I hear lefties claim they will vote for Trump because he will be so much easier to beat than Cruz . . . or because they hate Cruz worse with his inflexible interpretation of the constitution and all that . . .
It appears to me that Cruz’ interpretation of the constitution is pretty flexible; Article II, I, 5 for example is endlessly flexible to the point of meaninglessness!