If you were a betting person, what would you place the odds of Donald Trump running for reelection in 2020, losing the electoral college vote, and then (i) publicly conceding and (ii) acknowledging the election as legitimate and untainted? This would produce a sequence of events akin to every other change in administration in US history, notwithstanding impeachment or assassination.
I figure it's (80% that he makes it through four years without impeachment) x (70% that he runs for reelection) x (75% that he loses the election) x (40% that he recognizes the election as legitimate) x (80% that he nevertheless yields to a transfer of power to the next administration).
.8 x .7 x .75 x .4 x .8, for a grand total of 13%
And, yes, this is a un-substantive, vapid Trump discussion.