I think there's a lot of Trump hatred out there. As a result, I think the Dems will be very motivated in 2020. Further, I think Trump beat an incredibly flawed candidate in Hillary Clinton -- in fact, she might have been the only candidate he could have beaten and he only got 46.1% of the vote despite how horrible she was as a candidate. I just think he'll have to increase beyond his base to reach 270 electoral votes in 2020. JMO because.......
I think things fell extremely right for Trump in 2016. Michigan, Wisconsin and Pennsylvania account for 46 electoral votes. This election was effectively decided by 107,000 people in these three states. Trump won the popular vote there by that combined amount. That amounts to 0.09 percent of all votes cast in this election. If Clinton had won these states, she could have sealed the presidency with 274 total electoral votes.
I expect the next Democratic candidate will be better than Hillary, probably much better. I think he needs to expand his base yet I've seen virtually nothing that he's done to increase his base. I have it at 3-1 that he won't serve a second term. Not surprisingly, I've found no one who wants to take the other side.
You are more optimistic than the dems are. They have absolutely no good candidate. Hillary would jump at the chance but I think even the dems are too smart to put her out there again.
Then we have the old commie, Bernie, who will be about 100 and we have 'handsy' Biden.
Or they could go with an unknown rising star like .... well ... thinking, thinking.
As for Trump running again, when he first won, I thought he would hate the job, hate the pressure, hate having to live in the White House and work every day.
But, I was wrong. He's risen to every occasion and in spite of all the unfair press and attacks from unworthy people, he retains enthusiasm and Insouciance.
You may hate him, he may embarrass you but, hey, I think he will run again and win.