Mitt Romney effectively endorsed John Kasich in Ohio a week and a half ago, so this isn't really news barring a major statement. I wouldn't be surprised if he had offered to campaign with Rubio in Florida.
Of course, maybe Rubio advised Romney to self-deport to Ohio in a secret effort to sabotage the Kasich campaign?
The thing is Rubio is losing Florida by 20, why would he want to effectively hand Trump the nomination?
I mean, I'm being facetious, but I imagine that Rubio's relationship with John Kasich isn't a great one. I wouldn't put it past him to deny Kasich the nomination out of spite, and can almost imagine him endorsing Ted Cruz rather than Kasich if he supports anyone after dropping out. (Maybe that's why he looked so shell-shocked yesterday.)
