Well, to answer that we simply review the breakdown of voters.
First, in this post, by race. If "average" Americans are voting then it should be the case that voting percentages among the racial categories are similar to the overall voting rate (recall: 58%) and to each other.
Except they are not:
So, of the 58% of the population that voted:
- 66% of the white population voted;
- 56% of the black population voted;
- 30% of the asian population voted;
- 28% of the hispanic population voted.