President Donald Trump's pardon of former Arizona Sheriff Joe Arpaio has stirred up a hornet's nest. The pardon is certainly controversial and admittedly unusual, coming even before a court had imposed a sentence. But Trump's action, whatever its merits, is by no means unprecedented. Presidents have in the past used their pardon power to interrupt a criminal prosecution and deliver a political message — and not always a popular one.

To understand how Trump's action fits within the framework of pardons past, consider another case in which law enforcement officials were similarly charged with civil-rights violations. In March 1981, only weeks into his first term, President Ronald Reagan pardoned W. Mark Felt and Edward S. Miller, two high-ranking FBI officials then appealing a conviction for their roles in approving so-called black-bag jobs to spy on members of the Weather Underground through illegal wiretaps and break-ins. Like the Arpaio pardon, the Felt and Miller pardons fulfilled promises the president had made on the campaign trail; like Trump, Reagan argued that the pardons were justified by the two men's long careers in government — though he stopped short of commending their actions. (Felt later admitted that he was "Deep Throat," the key source for Washington Post reporters Bob Woodward and Carl Bernstein as they uncovered the Watergate scandal.)

A number of high-profile pardons since then have taken on a political tone, including President George H.W. Bush's Iran-contra pardons and President George W. Bush's commutation of I. Lewis "Scooter" Libby's prison sentence. Like the Arpaio pardon, these grants were not handled through the established Justice Department pardon process, and they stirred similar outrage.

But focusing on the political message sent by the Arpaio pardon obscures a more fundamental problem with pardoning in today's federal system: It has all but ceased to play the role the framers intended of advancing fairness and proportionality. Until about 40 years ago, hundreds of pardons were granted each year to ordinary people convicted of garden-variety crimes. A substantial percentage of those who applied for this official forgiveness received it.

But since about 1980, pardoning has become irregular and increasingly arbitrary, with grant rates in the single digits and processing times extending for years. President Barack Obama, for example, used the pardon power to commute many long prison sentences, but he largely neglected the cases of people who had completed their sentences and were seeking relief from their convictions' lingering civil consequences and social stigma.

The result of this neglect is that more than 2,000 applications for full pardon are pending in the Justice Department, with no sign that any will soon be granted. At the same time, there has never been a greater need for some mechanism in the federal justice system to mitigate the damage done to our social fabric by decades of mass prosecution. It is encouraging that in the past half-dozen years, almost every state has enacted some form of relief from so-called collateral consequences. But there has been no similar interest in Congress in creating a statutory alternative to pardon that would mitigate or avoid collateral consequences for federal offenders.

Meanwhile, the Justice Department, the longtime gatekeeper of the pardon power, continues to hold it in an iron grip. This disadvantages not only individuals seeking official forgiveness but also the person responsible for dispensing it. In failing to encourage the president in the regular and respectable use of his constitutional power, the Justice Department has instead encouraged its abuse.

Rather than seeing presidential pardons as a way to recognize the redemptive power of the justice system, federal prosecutors have often regarded pardons with suspicion — as antithetical and even threatening to what they do. This attitude has ill-served three successive presidents and resulted in an administrative system that is inefficient, arbitrary and unfair.

It's time we reconnect with the original values laid out for presidential pardons — what Alexander Hamilton described as "the benign prerogative." If the Arpaio pardon provides the occasion for getting such a conversation started, it will have done both the presidency and the nation a great service.

Margaret Colgate Love served as U.S. pardon attorney from 1990 to 1997 and now represents applicants for presidential pardon. She wrote this article for the Washington Post.