I'm staying the course. If anything, it seems like Trump in office is holding the market down from where it wants to be/ would have been with more stability. Every time he hasn't directly threatened nuclear war or failed miserably to pass something we are seeing pretty good growth.
There will clearly be a drop at some point while he is in office, whether due to war, impeachment, hacking, recession, constitutional crisis, etc. But it seems like the underlying economy is still strong and those things will likely be temporary. Individual presidents have little influence on the overall economy (though that doesn't stop them from taking credit for gains and blaming their predecessors for losses).
(I freaked out when Trump was elected and tried to convince my husband to sell our taxable account so we'd at least have some money to go have fun for a while. Luckily, he talked me out of it. Then I watched it go up, and up, and up. Lesson learned.)
So, I'm staying the course. I fully expect it to get pretty ugly for a while. I also think/hope we will recover from it.