I don't think the Democrats lose any ground in 2020, and if they do, it is a strategic retreat. The Democrats know that in 10 years they will run this country top to bottom due to demographic changes. The powers that be who pull the strings behind the curtain know this as well. So if the Democrats have to push a message in 2020 that costs them a few seats, but the message angers old aged Trump voters and excites 15 year old immigrants, then they will be rewarded greatly for that for the next 60 years.
I get it, I get it, no matter what happens the world is ending, the Dems win (even if they lose) and Trump is a fraud and he will lose. Let's just cheer on the demise. Your lack of originality gets old.