Voters stand in line during the fourth day of early voting in North Miami, Tuesday, October 30, 2012, as Floridians cast their ballot seven days before Election Day. (AP Photo/Alan Diaz)

Throughout American history, restrictions on voter registration were a major tool of disenfranchisement. Before the passage of the Voting Rights Act in 1965, only a quarter of African-Americans in the South were registered to vote. Four years after the VRA outlawed literacy tests and other voter suppression devices, the number of black Southeners registered to vote had more than doubled.

Despite the transformative impact of the VRA, one of the most consequential laws in American history, obstacles to voter registration persisted. There were few locations at which to register, limited hours, recalcitrant county registrars, frequent voter purges and complex re-registration schemes. “Overall registration rates were lower in 1992 than in 1972,” notes a new report from Demos.

Voting rights reformers, led by CUNY professor Frances Fox Piven, launched a campaign in the 1980s to make voter registration easier as a way to fulfill the long-overdue promise of the VRA. On May 20, 1993, President Clinton signed the National Voter Registration Act, which made it possible to register to vote at the DMV and other public agencies, such as public assistance and disability centers, allowed prospective voters to mail in voter registration forms and made it simpler for third-party groups to conduct voter registration drives. In its first year on the books, in 1995, over 30 million people registered to vote or updated their voter registration through the NVRA. “Since the implementation of the NVRA, an estimated 141 million Americans have applied to get on the voter rolls through registration services the NVRA requires at DMVs, disability offices, and public agencies,” reports Project Vote. “In addition, countless more have been protected from purging due to the protections the NVRA provides.”

Much progress has been made as we mark the 20th anniversary of the NVRA, but there’s still a long way to go. A quarter of eligible US citizens are not registered to vote. As Attorney General Eric Holder has noted, 80 percent of the 75 million eligible Americans who didn’t vote in 2008 were not registered to vote. States in recent years have escalated attacks on voter registration.

Following the 2010 election, Alabama, Kansas and Tennessee passed laws requiring proof of citizenship to register to vote (according to a 2006 study by the Brennan Center for Justice, at least 7 percent of eligible voters “do not have ready access to the documents needed to prove citizenship”), Florida and Texas made it virtually impossible for third-party groups like the League of Women Voters to conduct voter registration drives and states like Florida and Colorado attempted ill-considered and inaccurate eleventh-hour voter purges. The Supreme Court will soon rule whether Arizona’s 2004 proof of citizenship law violates the NVRA. And the Court will also decide next month whether the centerpiece of the Voting Rights Act is unconstitutional.

An antiquated voter registration system is a major cause of the country’s electoral dysfunction. Modernizing voter registration, as the Brennan Center for Justice has proposed, would add 50 million eligible Americans to the voter rolls by automatically registering consenting adults to vote at government agencies, adopting Election Day voter registration, and allowing citizens to register to vote and update their addresses online. These ideas have been incorporated into the Congressional Voter Empowerment Act and have recently been adopted by states like Colorado that are leading the way in terms of making it easier to vote.

“I think there is a guideline for election reform which we should take very seriously, and that is it has to be as simple as possible,” says Piven. “The procedures have to be as simple as possible so that people can understand them and can defend their own rights and so advocates can help them defend their own rights.”

What is Alabama’s problem with the Voting Right Act? Brentin Mock finds out.