This is a good and reasonable post from a Republican...thanks for that.
I have been impressed with Romney MOSTLY with regard to his stance on Trump. He has said negative things before about Trump, but he has stopped short of really doing much more than that, so we will see how big of a voice he can actually be here. Also, while I disagree with him on some policy issues, I could be ok with him as a President, because I do believe him to be a good person.
I do not think though that he could get elected. There are still too many Republicans who believe Mormons are not Christians, and they would stay away from the polls if Romney were the candidate.
Finally, a scandal in a political party keeps the party down for the next election, even if the object of the scandal is not there.
It would be quite a story for ANY Republican to win the 2020 election. Democrats can still mess it up and fail to win in 2020, but right now, whoever wins the Democrat nomination is in the driver's seat.