The constitutional pardon power is best known for its association with historic events like Watergate, which is why it is generally discussed in terms of the worthiness of its beneficiaries, rather than the god-like authority it vests in the president alone. There are only theoretical restrictions on the scope of federal lawbreaking the president has the power to forgive. But precisely because the power is so broadly applicable, and so narrowly held, its potential for abuse is tightly circumscribed by politics. Presidents might be tempted to pardon many people, but few want to answer for why this or that high-profile felon or suspect deserves leniency when others don’t.

There is a regular exception to this dynamic, though. The end of every presidency eases political constraints considerably, and makes the pardon power a potential source of incredible good or, as in Bill Clinton’s pardon of Marc Rich, gross impropriety.

President Barack Obama has been relatively stingy with the pardon power over the past eight years, but he has an important opportunity in this final week of his presidency to use the power in a way that pays lasting political dividends, and signals his belief that the Trump era will be a trying one for liberal democracy.

Even Edward Snowden’s most strident critics must now accept that his surveillance state disclosures, though illegal, were historically significant. The revelation that the National Security Agency engaged in the bulk collection of metadata logging the communications of nearly all Americans was particularly explosive in the U.S.; the all-seeing power of XKeyscore, which, per Snowden’s leaks, gives spies access to Internet user data all over the world, had a chilling effect on dissidents, journalists, and others both here and abroad. Taken together Snowden revealed an incongruity between what the public wants done in its name (or to the public itself) and what the government is doing, making him the totem for an international privacy movement.

As the extent of the impact he had on the debate over government and corporate data collection became clear, his critics and sympathizers sorted themselves into three main camps.

The intelligence community as a whole, along with advocates of vast U.S. national security power, are stridently anti-Snowden. Some accuse him of treason and want him returned to the United States in the hope that after a secret trial, he will spend the rest of his life in prison.

Another camp of elites believes Snowden is an admirable figure in certain ways, but should face some legal sanction for violating the law—if only to avoid creating a moral hazard that inspires future Snowdens who might not be as conscientious or well-motivated as he was. (This camp also includes politicians who fear alienating more clearly anti- and pro-Snowden cohorts.)

Then, of course, many people believe Snowden is a hero who deserves a full pardon.

Thus, the influential faction of Snowden foes is largely unified, while his sympathizers are not. Whatever Obama’s private views, he has never seen eye-to-eye with pardon advocates. Obama is an institutionalist and has pursued leakers zealously. He’s also been mindful of the political downsides of getting crosswise with the intelligence community, where whistleblowers are widely despised. But Obama has also conceded that Snowden “raised some legitimate concerns.”

Obama’s old friend and former Attorney General Eric Holder, who is said to be an exponent of ideas Obama shares but can’t articulate publicly, described the disclosures as a “public service,” but one that was nonetheless provided illegally. “He’s broken the law in my view,” Holder said. “He needs to get lawyers, come on back, and decide, see what he wants to do: Go to trial, try to cut a deal. I think there has to be a consequence for what he has done.”

These comments suggest Obama is in camp two; that if Snowden had returned to the U.S., the Obama administration might have been amenable to a plea bargain or some other form of leniency.

It is important for everyone who’s inclined to leniency, Obama in particular, to recognize that this option is for all practical purposes now closed. Between now and Friday at noon, when Donald Trump is inaugurated, the choice confronting Snowden sympathizers is binary: a pardon that allows him to return home (or to a different country) from Russia, where he lives in exile, or abandoning him to the mercy of a Trump-Putin alliance. This choice is obvious.

Had Hillary Clinton won the presidency, Snowden’s value to the Vladimir Putin—as a thumb in the eye of the U.S. government—would have remained unchanged, and bought all parties another four or eight years to consider a range of options.

But Trump’s victory throws Snowden’s status into deep uncertainty. The president-elect clearly feels unencumbered from antagonizing the intelligence community. But his pronouncements about Snowden have been uniformly critical and vindictive.

Trump may well seek rapprochement with the intelligence community, and cutting a deal with Putin (say, trading certain sanctions for Snowden’s immediate repatriation) would be an easy way for Trump to mitigate a big governing problem for himself and deal Snowden the punishment Trump says he deserves. There will be no plea bargaining or commutation. Snowden could easily find himself facing life in prison; if the Trump era is as vindictive and authoritarian as it has the potential to be, he might be put to death.

Granting Snowden a pardon might not conform to Obama’s ideal of proper justice, but that ideal likely can no longer be reached. And to the extent that his inhibitions are political, they are also moot now. He doesn’t need to appease the intelligence community anymore. And he’d offer young voters a big substantive and symbolic reason to become or remain engaged in liberal politics.

Obama would face a lot of criticism for pardoning Snowden, and not all Democrats would praise the decision. But as the organizing principle of their party becomes resistance to Trump, Democrats might eventually be grateful to have an eloquent person with a big megaphone inspiring people to participate. Over time, the decision to pardon Snowden is likely to wear very well. Obama should do it this week, while he still has the power.