I'm not saying this out of bias, because as a moderate I've voted for Republicans before. (Not that I consider Trump a Republican or Democrat, I think of him as in it for himself) - but I don't think in the Post WW1 era there has ever been a President who is more unlikely to get a second term. I mean... are we serious, the people who defend him are like cult members (not conservatives, just the ones who blindly defend him in the face of facts). He is the most wildly incompetent and embarrassing leader this nation has literally ever had. His policies are incoherent, without logic. I think worst of all what will hurt him is the fact he is so blatantly in it for himself and himself alone. Some voters overlooked that in 2016 assuming that he would do good for the country in order to make himself come across well but with his accomplishments few and far between the average swing voter will have less tolerance for his self serving bullsh**t than they did in '16.
He won the electoral collage on the basis of three states that he won by a combine roughly 70,000 votes and that was with a major late October surprise in his favor, against an opponent with very high unfavorables ... the chances of him hitting that jackpot again are very slim.
The only reason people are giving him a shot in 2020 is cause they are trigger shy after the fluke upset of 2016.
But realistically he has the worst hopes of reelection any incumbent has EVER had. He's toast. It won't be a traditional landslide cause of how polarized the country is but it will be the closest thing to a landslide you can have nowadays.