Dan I don't think your return is over one month, I think it is the ultimate nominee in November that counts. I agree both look 100% to win their conventions. Hillary, I can explain. Apparently there is an outside chance she will be indicted on those emails before November. That would rule her out of the election. Note that Joe Biden is reckoned to be as likely a beneficiary as the Bern.
The Donald is harder to explain. Yes you have mentioned a few possibilities but not sufficient to justify 4% (illness at age 70? possible). There is possibly a slight chance that he will make one unforgivable howler that would force the grandees to dump him.