Washington (CNN) -- U.S. Attorney General Eric Holder said Tuesday that if the Justice Department were faced with budget cuts due to sequestration, he believes that he would be able to maintain public safety by shifting resources and that the federal prison system could operate "for months" if necessary.
"I have the flexibility to move funds within the Department," Holder said.
However, nearly all civil cases would have to be put on hold, he added during an extended interview with National Public Radio reporter Nina Totenberg after giving an address at the John F. Kennedy Presidential Library in Boston.
In the speech, Holder discussed voting rights and defended his department's challenges of voting regulations in Texas, South Carolina and Florida. He said those cases show that Section 5 of the Voting Rights Act that requires federal approval of changes in voting procedures in 16 states, mostly in the South, must be maintained.
Critics have said the provision is no longer needed because minority voting rights have become accepted. But Holder said the states "with documented histories of discrimination" still should be required to gain "pre-clearance" from the Justice Department or a panel of federal judges.
"Despite the remarkable, once unimaginable progress that we've seen over the last half century — indeed over the last four years — Section 5 remains an indispensable tool for eradicating racial discrimination," Holder said.
Holder continued to press for increased voter registration. He rejected the common Republican claim that concerns about potential voter fraud require tight controls on voting systems.
"In-person voter fraud remains rare," he said. "The alleged tension between having accessible election systems and having election systems that are free from fraud is simply not real."
Holder discussed other subjects in a question-and-answer session, including the legalization of marijuana in Colorado and Washington state. He said he is not close to making a policy decision and held a meeting Tuesday to study the laws. He said he may have a decision in a "month or so, give or take a holiday period."
Holder made no announcements about his future in the Obama administration but said he still has issues he would like to work on before departing. One time-consuming issue involves a potential overhaul of the criminal justice system. Holder said there is a need to consider whether the right people are in jail, whether sentences are appropriate and what changes can be made. He also said compassionate releases for older, dying prisoners must be examined.
On gay marriage, Holder said only that the decision not to defend the Defense of Marriage Act was made entirely within the Justice Department. He recalled taking the decision to the White House, and President Barack Obama agreed. "If he hadn't, it would have been interesting," Holder said.