This seems to be the most obvious way forward for Kasich now.
Spend the remaining dough and momentum to run up the numbers, then cash in by dropping out and endorsing Rubio in exchange for the VP spot.
Only question is if Rubio already promised it to Nikki...
It's close to 100% certain that Haley, if she doesn't mind, will be Rubio's pick for the VP slot. Even for a giant like Hillary, it's gonna be really, really difficult to beat a ticket consisting of Rubio and Haley, the two most optimistic, modern, future-embracing Republican politicians for the past 60 years or so.
Frankly I think Kasich brings significantly more to both the ticket and the administration than Haley does.
Haley is just an OK governor and has minimal other experience. Kasich has tons of experience and can work with Congress, with Rubio has already shown he can't do.
Also, Rubio has foreign policy chops but little domestic policy skill. Kasich is all about that domestic policy.
Kasich is also a very optimistic fellow and has gotten pretty good at showing that on the campaign trail.
I'm not Rubio needs more of the young/minority image. Diminishing returns there.
Kasich also has a lot of Democrat and Independent fans. He might convince some of them to cross over.
Also, Ohio.