Voting is the bedrock of democracy. However, because the right to vote is not defined or secured in the Constitution, states and local governments have broad leeway to implement their own rules about voter registration and time and manner of elections. Voting rules have been an area of controversy and rapid change in recent decades, with states moving both to expand voting rights and participation, such as through automatic voter registration, and others moving to restrict it further, in the name of preventing voter fraud, which is rare.
In all but one state (North Dakota), voters must register before casting a ballot. However, state laws on how and when a voter can register vary widely, and include innovations such as same-day registration, automatic registration when a citizen interacts with any government agency, and online registration.
For the process of voting itself, states have innovated by allowing early voting, vote-by-mail, and no-excuse absentee ballots.