This blogpost first appeared on the blog of the American Constitution Society.

This November's presidential election will present a stark choice between President Barack Obama and a Republican challenger, and voter turnout analysts predict a decline in voter turnout from our 62 percent turnout of eligible voters in 2008.

Voter motivation is one reason why American turnout lags behind that of many nations. Most Americans experience limited choice and a relatively low chance of electing strongly favored candidates. For example, in 2010 only one in four eligible voters elected a Member of the U.S. House of Representatives (what we call "the Representation Index"). In contrast, in Denmark's last elections, nearly five in six eligible voters elected representatives to its national legislature from an array of choices, voter turnout was more than 85 percent, and its system of proportional representation led to more than 95 percent of voters electing their preferred choice.

Our broken voter registration system is a more direct barrier to participation. In fact, if every single registered voter participated this November, we still would trail many nations in turnout. According to a new study by the Pew Center on the States Election Initiatives, of some 220 million eligible American votes, more than 50 million aren't registered to vote. Another 24 million voter registrations have serious data problems that could block or interfere with voting.

It won't take rocket science to ensure that every eligible voter is registered to vote and that all ineligible voters are not. What we need is a national commitment to take on the challenge, some start-up resources and smart use of existing databases. Other countries continue to modernize their systems, with international norms for voter registration rates typically well above 90 percent of eligible voters.

Two nations provide recent examples of how it can be done. Chile last month adopted a law designed to register all eligible voters automatically. In its last presidential election in 2010, nearly a third of Chile's 12 million voting-age citizens weren't registered. With the new law, more than 4.5 million voters, mostly young adults, will be added to the voter rolls.

Egypt provides another example. After decades of authoritarian rule, the "Arab Spring" movement took hold in Egypt, leading to a new election, for which the interim government established a universal voter registration system. Every Egyptian who was at least 16 years old was entered into a national voter database based on addresses on their required national identification card. Voters who are at least 18 years or older need only show their national identification card at the polls in order to vote.

American citizens do not have a national ID card and are not voting in the wake of a revolution, yet Chile and Egypt provide a general roadmap for action. All Americans should automatically obtain a kind of"democracy passport" at no cost upon becoming citizens. That "passport" need not be a physical piece of paper, of course, but rather an indication of a national commitment to ensure and protect equal access to suffrage. Lifetime voter registration would require a unique identifier for the specific purpose of participating in U.S. elections. The passport metaphor would go hand-in-hand with establishing innovative civic education programs designed to prepare all Americans to be active, informed voters - establishing that preparation for political participation is as important as preparation for economic contributions.

Even without a national policy to secure full and accurate voting roles, states are making major advances. As the Pew Center on the States' David Becker explained when releasing their new report, "antiquated, paper-based systems are plagued with errors and inefficiencies." Fortunately, however, "[p]roven solutions and technology are already in place in many government offices and the private sector, and states can use them to improve the accuracy, efficiency, and cost-effectiveness of their systems. State leaders from across the country and from both parties are pioneering these solutions."

Seeing how some states are making these improvements and how nations like Chile and Egypt haves soared past the United States in terms of both the access and integrity of their voter registration systems is a sobering reminder that the status quo is unacceptable. Without what ultimately should be a nationally coherent system of universal voter registration, we cannot ensure two basic goals of a fully representative democracy: that no ineligible vote should be cast, and that every eligible voter should have secure access to voting. It's time to make a national commitment to voting in the United States; doing so must include modernizing voter registration.