U.S. Attorney General Eric Holder. Holder announced his resignation on 25 September, but plans to remain in office until his replacement is confirmed. (Michael Reynolds/EPA)

THE REACTION to Attorney General Eric H. Holder Jr.’s decision to resign after six years in office gives a flavor of the challenges he has faced. Many on the right responded with denunciations centering on the usual litany of phony scandals. Some on the left offered grudging praise before turning to their own denunciations for Mr. Holder’s insufficient devotion to their various causes. Attention quickly wheeled to the next battle, over confirmation of Mr. Holder’s (still unnamed, but never mind that) replacement.

Like everyone, we’ve had disappointments with Mr. Holder’s record, and we don’t presume to predict how history will rank his tenure. But amid all the noise, we think it’s important to note the substantial contribution he has made in a core element of an attorney general’s job, the protection of civil rights. His passion for that responsibility expressed itself especially in four areas: defending all Americans’ right to vote; making sentencing and other aspects of the criminal justice system fairer and more color-blind; protecting immigrants from undue harassment; and hastening full equality for gay and lesbian Americans.

Not surprisingly, perhaps, our list of disappointments is headed by Mr. Holder’s pursuit of leakers and the journalists who receive leaks; this administration allowed its concern for national security to outweigh beyond prudence its responsibility to safeguard freedom of expression. We also have thought his department moved too slowly in the fight against rape in prison and too zealously, especially in Louisiana, against parents’ right to choose the schools their children will attend. His support for D.C. voting rights, like President Obama’s, has been tepid. We hope the next attorney general will add the wild overuse of solitary confinement in U.S. prisons to his or her urgent to-do list, and we think there’s more work to do in encouraging the FBI, the New York Police Department, the Bureau of Alcohol, Tobacco, Firearms and Explosives and other law enforcement agencies, both inside and outside the Justice Department, to cooperate, especially on counterterrorism.

But these complaints are easily outweighed, for us, by Mr. Holder’s accomplishments. In an era when Republicans at the state level seem unembarrassed to try almost any strategem to deprive minorities and young people — read: Democrats — of the franchise, Mr. Holder has been a fierce champion of the opposite principle: Democracy depends on everyone having unencumbered access to the voting booth. After decades of rising incarceration rates and racial disparity in sentencing, Mr. Holder has been at the forefront of a movement to restore sanity and equity to punishment. He resisted state laws that targeted immigrants or people who police might think look like immigrants. And in refusing to defend the Defense of Marriage Act, and then, after the Supreme Court vindicated that call, in scouring and rewriting the federal rulebook to promote equal treatment of same-sex marriages, he played a key and honorable part in the unfolding movement toward recognition of lesbian, gay, bisexual and transgender Americans as full citizens.