By any measure, Jeff Sessions has done a standout job as attorney general

Serving as U.S. attorney general is the honor and the challenge of a lifetime.

We are three former attorneys general who served in Republican administrations — from different backgrounds, with different perspectives and who took different actions while in office.

But we share the view that Jeff Sessions, who resigned at President Donald Trump's request on Wednesday, has been an outstanding attorney general.

Each of us has known Sessions over many years. All of us thought his record — as a U.S. attorney for 12 years, as a state attorney general, as a respected U.S. senator for 20 years — made him a nominee of unexcelled experience. As important, his deep commitment to the Justice Department and its mission made him a nominee of unexcelled temperament.

By any measure, he has fulfilled the promise of those qualifications.

Sessions took office after the previous administration's policies had undermined police morale, with the spreading "Ferguson effect" causing officers to shy away from proactive policing out of fear of prosecution. Steep declines in the rate of violent crime from 1992 to 2014 were reversed in the last administration's final two years, with violent crime generally up 7 percent, assault 10 percent, rape nearly 11 percent and murder 21 percent. Opioid abuse skyrocketed. Many people were concerned that the hard-won progress of earlier years would be lost.

Sessions made sure that didn't happen. He reinstituted the charging practices that had been used against drug dealers before 2008. He leveraged the power of big data to locate those who were stealing taxpayer dollars and flooding the streets with opioids and other painkillers.

In 2017, the department prosecuted the most firearms defendants in 10 years, since another of us (Michael B. Mukasey) was attorney general, and in 2018 it prosecuted the most firearms defendants ever, surpassing the prior mark by 17 percent.

Sessions set four goals for his tenure: to reduce the rates of murder, violent crime generally, opioid prescription fraud and drug overdose deaths. He achieved all four.

He attacked the rampant illegality that riddled our immigration system, breaking the record for prosecution of illegal-entry cases and increasing by 38 percent the prosecution of deported immigrants who re-entered the country illegally.

Such numbers are impressive, but just as impressive has been the refocusing of the department's efforts under Sessions' leadership to protect the liberties of Americans.

In statements of interest in four cases, the Justice Department served notice that it would act to fulfill Sessions' commitment to promote and defend "Americans' first freedom" — the freedom of speech — at public universities, by opposing efforts to impose unconstitutional limitations on speech and speakers who allegedly offended the sensibilities of some on campus.

To help restore the rule of law, Sessions has opposed sweeping nationwide injunctions by federal district courts; forbidden settlements in which the Justice Department has directed payments from settling defendants to third parties so as to circumvent the appropriation authority of Congress; withdrawn policies that expanded statutory protections based on gender identity that Congress had not provided for in law; and rescinded guidance documents previously issued by the Justice Department that were outdated, inconsistent with existing law or otherwise improper.

He has acted to protect our national security through such diverse steps as cracking down on leaks through the National Insider Threat Task Force; establishing the Hezbollah Financing and Narcoterrorism Team to combat the threat from Hezbollah narcoterrorism; and supporting reauthorization of the Foreign Intelligence Surveillance Act to permit the intelligence community, under robust oversight by all three branches of government, to collect vital information about international terrorists and other foreign intelligence targets.

Throughout, Jeff Sessions has set an example of personal grace and dignity under enormous pressure. He has remained humble and of good cheer, on good days and bad, and focused on fulfilling the mandate of the administration in which he has served. He has acted always out of concern not for his personal legacy but rather for the legacy of the Justice Department and the rule of law. We salute him for a job well done.