i think there is a very high chance dems do very well in the midterms, as historically that always happens. that has less to do with trump though and is a natural american political pattern where we like gridlock, and the party that is happier is less motivated.
however "doing well" can still be a very wide range and we don't have enough data to support what will happen a few months out right now. Now, I know I literally made all these same arguments in 2016 and was completely ignored by liberals here, but I would remind you to not make the same mistakes you did last time. Remember, it was just as "obvious" to you guys back then that you were going to destroy trump.
that said, the midterms are not going to come down to trumps comment on omarosa. Trump knows what he is doing at this point and this is a classic outrage trap that he's set for you liberals, and you fall for them every time. He says a phrase, which can be perceived as harmless or a slight insult at worse, and then you guys will start writing articles about how calling people dogs is racist, sexist, and how people should check their animal privilege, and you'll overplay your hand until people start rolling your eyes. This has happened so many times now, but if you aren't woke like me then I might be talking leagues beyond your comprehension.