Cruz is in a race. He is the ONLY candidate to win over 50% in ANY state, and the GOP rules require 8 such simple majority wins. Trump has none. For months, many have been saying that Trump has a ceiling of about 50%, and he has only 46% of the delegates, and has never topped the 49.3% he got in MASS (and all his best numbers are in liberal states).
If Kasich gets out of the way, especially with all of the winner-take-all states remaining, Cruz can easily win enough delegates to capture the nomination before the Convention.... IF the conjecture of the Trump Ceiling is correct. If it is not, and Trump starts racking up simple majorities and a bunch of winner-take-all states, then he will have the nomination easily before July. Kasich departing is the only way we can avoid the Convention... and this is why he will not leave, despite being mathematically eliminated yesterday.
You misunderstood the rules. They have to win 50% of the delegates, not 50% of the raw vote. Cruz has 4 qualifying states, Trump has 10.
Exactly