All that is needed is for Cruz and Kasich to get about 225-250 more bound delegates. Cruz should get about 150 from IN, NE, SD and MT. They should easily get the rest from the proportional states.
It’s doable. The GOP establishment would rather have the Clintons in the White House than Trump as their candidate. They would do that. They know that many Trump supporters would back him in a third party run. They don’t care. They won’t turn the Republican Party over to Trump.
Cruz is favored to win California!!