The United States Supreme Court has held that California's disenfranchisement of convicted felons who have completed their sentences and paroles did not violate the equal protection clause of the fourteenth amendment.
Richardson v. Ramirez, 94 S. Ct. 2655 (1974).
Anne M. Nelson,
Constitutional Law - Fourteenth Amendment - Equal Protection - Voting Rights of Ex-Felons,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol13/iss1/16