Michelle Obama says protecting the right to vote has become the nation's most important civil rights issue.

The first lady tells a gathering of black lawmakers and leaders that they owe it to those who fought and died for equal rights in the 1960s to make sure every voter can freely cast a ballot.

Her comments at an annual awards banquet for the Congressional Black Caucus come amidst a push in more than a dozen states to pass laws requiring voters to show ID at the polls. Critics say the laws unfairly harm minorities, poor people and college students - all groups that tend to vote Democratic.

Comparing it to the civil rights movement, Obama calls voting rights "the march or our time" and "the sit in of our day."