OKLAHOMA CITY, Okla. (AP) — A new study has found that systemic barriers to voting on tribal lands contribute to substantial disparities in Native American turnout, particularly for presidential elections. The study, released Tuesday by the Brennan Center for Justice, looked at 21 states with federally recognized tribal lands that have a population of at least 5,000 and where more than 20% of residents identify as American Indian or Alaska Native. Researchers found that between 2012 and 2022, voter participation in federal elections was 7 percentage points lower in midterms and 15 percentage points lower in presidential elections than among those living off tribal lands in the same states. Earlier studies show voter turnout for communities of color is higher in areas where their ethnic group is the majority, but…