John R. Lewis Voting Rights Advancement Act of 2021 This bill establishes new criteria for determining which states and political subdivisions must obtain preclearance before changes to voting practices may take effect. Preclearance is the process of receiving preapproval from the Department of Justice (DOJ) or the U.S. District Court for the District of Columbia before making legal changes that would affect voting rights. A state and all of its political subdivisions shall be subject to preclearance of voting practice changes for a 10-year period if 15 or more voting rights violations occurred in the state during the previous 25 years; 10 or more violations occurred during the previous 25 years, at least 1 of which was committed by the state itself; or 3 or more violations occurred during the previous 25 years and the state administers the elections. A political subdivision as a separate unit shall also be subject to preclearance for a 10-year period if three or more voting rights violations occurred there during the previous 25 years. States and political subdivisions that meet certain thresholds regarding minority groups must preclear covered practices before implementation, such as changes to methods of election and redistricting. Further, states and political subdivisions must notify the public of changes to voting practices. Next, the bill authorizes DOJ to require states or political subdivisions to provide certain documents or answers to questions for enforcing voting rights. The bill also outlines factors courts must consider when hearing challenges to voting practices, such as the extent of any history of official voting discrimination in the state or political subdivision.