Studies of elections in two states indicate some disparities for both minority voters as well as some other groups.
A study of Florida's 2016 election found that ballots mailed by members of racial minorities were 2 1/2 times more likely to be rejected than those cast by whites. Voters under 30 mailed in 9.2% of all absentee ballots but accounted for 30.8% of rejections.
Rejection rates across Florida's 67 counties were inconsistent, suggesting a disorganized approach to ballot counts.
Similarly, in Georgia's 2018 midterms, minority, young, female and recently-registered voters were all more likely to have their ballots rejected.