Two rats that no one cares about.
I believe Romney is positioning himself in the event Trump meets an untimely demise. Anyone that knows history knows that Trump is repeating much of the history that led to JFK's death. He would seize the moment and jump in at that point.
Kasich on the other hand is just a dumb stump, a pimple on the *ss of life.
Worst case scenario, one I fear more than anything else, and Romney steps in like Hubert Humphrey, when Robert Kennedy was taken out in 1968. If it ends up being him, even AOC wold beat him.