There are his declared aims, as described through the election.
But I think the main one is that he appears completely self-centred and dishonest.
He also desperately wants adulation, so protests will probably influence his stance on any given topic. This has good and bad features.
His voters are beginning to find this out now. They were useful to get him into office. But now he is in, he's going to respond to the loudest voices. Which may not be theirs.
He's already changing his tune on Obamacare. I imagine a bunch of other promises will be broken.
My prediction. Mitch McConnell and Donald Trump are going to be at loggerheads for the next two years. The former thinks he will provide the policies and he can manipulate Trump into saying yes to everything he wants. Trump's never going to do that. And he will try to smash McConnell as he has sought to smash every other competing power base.
Of all the people I would enjoy seeing turfed out, the Machiavellian McConnell tops my list.