The bookies currently put Trump's odds of winning the election at 55%.
If Trump wins, it seems clear there's better than even odds of him successfully transforming the US into a fully autocratic state. There's some chance that the "resistance" put up by liberals and the extended state apparatus will have some measure of success, but the greater moderating factor on Trump's success would be as always his ignorance and extremely narrow self-interest.
That combines to at least 1/4th odds overall.