In the US it is public who voted, just not how they voted. But the combination of new census data, state electoral rolls and exit polls has given some insightful data into who voted in 2020.
Voting turnout went from 60% to 67%, so overall voters increased by over 10%. But some races had greater turnout.
- Asians up 39%
- Latinos up 31%
- Blacks up 14%
- Whites up 12%
The increase in support in each demographic for Biden over Clinton was:
- Whites +3%
- Blacks -3%
- Latinos -8%
So Biden gained with black voters but Trump gained with black and latino voters.
But even though Biden got a smaller percentage share of Blacks and Latinos he still got 90% and 63% of the vote from them and the big increase in voting numbers for them helped him.
In Georgia and Arizona the increased vote from black voters was larger than Biden’s margin of victory. So it was black turnout that won him those traditionally red states.
If you are into data, go look at the link. Masses of it.