So, I went to a talk by Sam Wang who does election polling and prediction research at Princeton University using statistical models (similar to Nate Silver) and he showed a model that supports a notion that Donald Trump actually
benefitted from Kasich winning Ohio. This is due to the notion that Kasich's victory ensures that he will stay in the race (whereas he would have dropped had he not won) and Trump, statistically, would do better when there is more competition to split the vote.
I go to a school that's literally less than ten minutes from Cincinnati, and the entire room moaned because a lot of people voted for Kasich to stop Trump...
EDIT: I can provide the picture of the graphs he provided on this note. The speaker's name is Sam Wang.