Trolling through news today I came across this CNN story…
Trump has a real shot of winning
If the 2020 race moved 8 points in Trump’s direction, he’d win.
You could even concentrate on just the most recent incumbent elections of 2004 and 2012. Like 2020, opinions of the incumbents (George W. Bush in 2004 and Barack Obama in 2012) were hardened early. The final national results in those races differed from the May polls by 3 and 4 points.