Democrats have said long waiting times at the polls in some heavily Democratic areas cost the party hundreds of thousands of votes in November. The most notorious example was in Florida where some polling stations in Miami stayed open for hours to accommodate everyone waiting in line.
Some studies have suggested waiting times tended to be significantly longer in areas with concentrations of black and Hispanic voters, The New York Times reported Tuesday.
Obama has notified Democratic leaders in Congress he will talk about making voting easier in his State of the Union message next week. Bills have already been introduced to mandate at least 15 days of early voting and on-line registration.
Republicans in many states passed legislation before the 2012 election requiring voters to show identification. The bills were described as measures to prevent voter fraud, but Democrats charged their real aim was to keep poor and minority voters from the polls.