Hillary at 38/55 favorables pretty much means that if the Republicans nominate a sane candidate she is done.
She has it in the bag.
I think your little formula, with zero wiggle room, results in the ineluctable conclusion, that to a 100% certainty, the Pubs will nominate an insane candidate. So the only question remaining, is by insane, do you mean legally insane (which varies by state, but we can get that later), or insane in some more colloquial sense (in which event we will need to flesh out what you mean). Look forward to hearing from you, on all of these most important and pressing issues.
Just playing along with the conmon liberal perception that half of this field is mentally challenged. Fortunately I am not a liberal.