Nobody will win, why? Because if you win a presidential election in a year that ends in zero you can expect to die in office, so if you win you lose.
I can't tell you why, but nobody has actually won an election in a zero year and lived to their retirement without getting shot. I have explained this in another post.
Trump and granny Clinton were 80 in 2016, so I don't believe they will be keen on a second term.
The way things have been going, you can bet on the next president being someone who was sentenced to life in prison.
Oh wait, the question says witch candidate, not which candidate.
Well if the Russian computer hackers can determine the outcome of an election, then I don't see why a Wiccan priestess who casts a spell on American can't.