The U.S. Supreme Court this week upheld Indiana's voter identification law requiring all voters to show a government-issued photo ID at the polls. A split decision by the justices, however, did little to quell the partisan debate over voter ID laws in state capitols and in Congress and could prompt another series of legal challenges in a number of states where lawmakers are considering similar changes, according to, a project of the Pew Center on the States. also released a chart detailing  voter ID laws in all 50 states.

In February, Pew released a report Back to Paper, that details how five states that implemented electronic voting have chosen or are considering statewide paper-based optical scan systems. The report explores the process by which California, Colorado, Florida, New Mexico and Ohio -- having adopted electronic voting systems -- subsequently decided to de-certify, re-examine or re-think their use.