One of the dumbest things on the economic front Trump has done has been to tie himself so close to the performance of the stock market. During the campaign, he called it a big, fat, ugly bubble. Now, he's hyper-focused on it. He's tweeting about it, bashing the Fed over it, and taking credit for it, every time he gets a chance. That's a dangerous game.
That said, I have no doubt that if Hillary would have been elected, the market would not have done as well. If it looks like someone like Warren will win in 2020, I expect it to take a substantial hit.
All that said, the performance of the market has been largely driven by cheap money, not because Trump or Obama. Neither have done or are doing much to fix the underlying structural issues, relating to the stability of our financial system. Instead, they have exacerbated the issues. You can thank the massive expansion of debt and low rates for papering over the issues and creating an environment for an overwhelming amount of malinvestment.
The chickens are going to come home to roost, and it isn't going to be pretty. They are deathly scared of a recession. You can see it every time the market starts to decline, there is a rate cut, a barrage of dovish Fed speakers, a Tweet about a trade deal with China, etc. to try and keep it from dropping. At some point, it will quit working...probably when corporate share buy-backs start to diminish. We may be getting close, unfortunately. We're also at or past peak employment. It's about time to buckle up.