I posted this list in another thread but it should be here too. People seem to forget how big the Trump wave was from 2012 to 2016 in WI, MI, PA, OH and IA, and that much of that disappeared already in 2018.
Michigan -0.2% (2012 to 2016 -9.7%)
Pennsylvania -0.7% (2012 to 2016 -6.1%)
Wisconsin -0.8% (2012 to 2016 -7.7%)
Florida -1.2% (2012 to 2016 -2.1%)
Arizona -3.5% (2012 to 2016 +5.6%)
North Carolina -3.7% (2012 to 2016 -1.7%)
Georgia -5.1% (2012 to 2016 +2.7%)
Ohio -8.1% (2012 to 2016 -11.1%)
Texas -9% (2012 to 2016 +6.8%)
Iowa -9.5% (2012 to 2016 -15.3%)
Over 4 years around 7.5 million voters die with Trump losing close to 5 million with a net loss of greater than 2 million votes. The 19 million new voters, mostly millennials and Zers, will swing hard to Democrats. Given a few Trump voters who will vote against him in 2020 he can only expect about 56 million votes from the ~63 million who voted for him in 2016. With 140 million total votes expected in 2020 he has to find over 14 million new voters to win the popular vote, out of the 19 million. That won't happen.
Given the underlying trend of Arizona and North Carolina toward democrats and deaths, MI, Pa, WI, AZ, and NC should vote against Trump. Florida will Florida, but I think they flip, particularly given the new former felon vote. Ohio, the Florida of the Midwest, will do their thing too, and I suspect they will stick with Trump
Only two states bought into Trump's populist lies more than Iowa, but they elected three democratic congressmen in 2018 and Trump's approval is 10 points below water there. I think they swing all the way back.
Georgia and Texas are trending hard toward the Democrats. I think this is the year they flip, but that may be wishful thinking. In Texas there will be 2 million or more voters vote who did not vote in 2018, and nearly 90% of them will come from the 10 largest counties that have swung hard toward the Democrats over the last 8 years. They will make it close, perhaps +/- 100,000 votes, or +/- 1%. Georgia should be just as close on a percentage basis.