WASHINGTON — Attorney General Eric H. Holder Jr. called Tuesday for the repeal of laws that prohibit millions of felons from voting, underscoring the Obama administration’s determination to elevate issues of criminal justice and race in the president’s second term and create a lasting civil rights legacy.

In a speech at Georgetown University, Mr. Holder described today’s prohibitions — which in some cases bar those convicted from voting for life — as a vestige of the racist policies of the South after the Civil War, when states used the criminal justice system to keep blacks from fully participating in society.

“Those swept up in this system too often had their rights rescinded, their dignity diminished, and the full measure of their citizenship revoked for the rest of their lives,” Mr. Holder said. “They could not vote.”

Mr. Holder has no authority to enact the changes he called for, given that states establish the rules under which people can vote. And state Republican leaders made clear that Mr. Holder’s remarks, made to a receptive audience at a civil rights conference, would not move them.