The racial and age splits have been there for some time, but the partisan split on both education and income seems to be changing in the age of Trump, with Republicans being less rich and with lower education levels than they were pre-Trump. I guess that alone might be useful to Dems in midterm elections, since higher income and better educated people are more reliable voters.
I think it is certainly possible to win the House but 2020 looks a better shot if Dems can get Gov. races & do gerrymandering - I think that itself will decide 20-25 seats !
But redistricting wouldn't happen until 2021/22, after the 2020 census. So I don't see how it's going to move seats in the 2020 elections.
