With Trump, Rubio, and Cruz in the race until the end, we're likely to get a brokered convention with superdelegates making the final call. If Trump has a plurality, he'll need to make some concession to the establishment for their support, which may very well mean picking Wind-Up Toy Rubio as VP. Even without a brokered convention, he may do it in order to win over pro-establishment voters in the general election, kind of like Reagan's concession to the Rockefeller Republican wing of the party when he picked George H.W. Bush as his running mate.
Hell, Schweiker was even worse ... marginally ...