61% college grads? That seems a tad too high.
Depends on how they're counting. In 2016, exit polls showed 50% with a bachelor's or higher, but 2018 was only 33%. Those same exit polls showed a 12-point education gap in 2016 and a 23-point one in 2018. There's definitely a possibility that both the shares and support levels of educated/non-educated are incorrect - especially since prior to 2016, GA's education gap was smaller (and even just a few years ago, reversed; Dems did better with non-college educated than college educated).
The poll number is definitely off (assuming they're not including associate degrees, some college, etc), but - assuming 2018 education gap (23 points) is more reflective of 2020 & the 2016 % of college graduates (50%) is more reflective than 2018 - the difference would be around 5 points.
So Biden +3, Sanders -1, Warren/Buttigieg -2, Harris -4, etc.