I feel that we can be optimistic. This election is proof that democracy exists, and that people *do* have a voice. The issue was, there wasn't a good candidate. I see 2020 (or earlier, depending on impeachment) having a lot more options, and a lot more voices. Trump, at the end of the day, has as much power as the people give him, and there will be enough republicans who will push back.
I also think Republicans might turn themselves around, and become something the educated middle class might vote for. It depends on whether Trump is going to go forward again for 2020, but I think they'll start to change.
I'll start to feel more scared if Le Pen gets traction with this. Having nationalists in charge is going to end in war.