Betcha non-white turnout in this one was light.
High white turn out, low non-white turn out is traditional in off year elections.
Also, whites have the highest voter eligibility, usually close to 80%.
Hispanics often have less than 40% eligible voters, usually because of citizenship and age issues.
Blacks have around 70% eligibility.
I will speculate that felony convictions play a significant part in that number.