Robby Mook, Hillary Clinton’s campaign manager, wrote a six-page memo to "Interested Parties" Wednesday on the state of the 2016 presidential race. His message: Everything is under control. "While we always have, and continue to, anticipate a very competitive race," Mook wrote, "Hillary stands today in a very enviable position."

He’s got to be kidding. Clinton faces mounting political and legal challenges that threaten her bid for the White House and the Democratic hold on the presidency. Her favorable ratings have tanked. Voters find her untrustworthy. She can’t fill overflow seats, but her socialist opponent enjoys huge crowds. Vice President Biden is thinking of challenging her. She’s the most inaccessible and aloof candidate running today.

And those aren’t her biggest problems. More worrisome for Clinton is the federal investigation into whether her private email server compromised national security. After months of resistance, she finally turned over the hardware, along with two thumb-drives of emails that Clinton lawyer David Kendall has been keeping, to the FBI. This week the bureau also visited a Colorado company that handled the emails. Clinton’s top aide, Huma Abedin, is lawyering up.

Clinton maintains she followed the rules. But she’s been proven wrong before. Who knows what the FBI and intelligence community might find—or how it might affect her campaign.

What Clinton needs most of all is a way out, a means of escape. Before she can recover politically, the legal uncertainty must end. And the only way to end it is a presidential pardon. Clinton’s future isn’t only tied to President Obama’s job approval and economic performance. It’s also tied to his compassion. Obama alone can resuscitate Hillary’s campaign.

You scoff. How can a president pardon someone who hasn’t been convicted of a crime? Well, it’s not like Obama has worried about the legality of his actions in the past. And besides, there’s a way for him to pardon Clinton. In a 2008 article, Slate magazine cited Ex parte Garland, a nineteenth century Supreme Court decision. "Generally speaking," wrote Jacob Leibenluft, "once an act has been committed, the president can issue a pardon at any time—regardless of whether charges have even been filed."

The most famous preemptive pardon in American history was of Richard Nixon. President Ford absolved his predecessor of all crimes he "has committed or may have committed or taken part in" between inauguration day 1969 and resignation day 1974. Obama could do better than Ford by absolving Clinton of all crimes she "has committed or may have committed or taken part in" between, say, January 20, 2009 and January 20, 2025. That would give her some wiggle room. And why not pardon Huma, too. She’s suffered enough.

A pardon is necessary because political pressure may not be enough to save Clinton. Investigations are unruly, unpredictable. "Even if the Department of Justice is highly politicized—as it is—there is a powerful legal procedure here that will be hard to kill off," writes University of Chicago professor Charles Lipson.

But the FBI inquiry will cease as soon as the pardon is issued. There’d be no reason to proceed—Clinton would be forgiven for whatever she did or might have done. Not to pardon her would risk another "long national nightmare" of I.G. reports, committee hearings, depositions, subpoenas, betrayals, media leaks, tell-all books, grand juries, and indictments. Bad press would dog her campaign. Republicans would benefit.

Not only would a pardon have legal consequences. It would have political ones. It would be a tacit endorsement of Clinton, a message to Biden not to run. Scrutiny of Clinton would fade. A few news outlets might continue to dig around—we at the Washington Free Beacon will never, ever stop—but most reporters, who’d rather not be writing about this scandal anyway, would turn elsewhere.

Obama would look magnanimous. The country would be spared years of Clinton drama it doesn’t want. A pardon would be a final display of Obama’s moral superiority to the woman he defeated long ago—exactly the sort of self-righteous gesture that most appeals to him. As David Geffen put it in 2007, "I don’t think anybody believes that in the last six years, all of a sudden Bill Clinton has become a different person." Nobody believed that about Clinton’s wife, either. They still don’t.

Pardon Hillary now if you want to save her campaign. If not, if you let the investigation proceed, then you may have no choice but to pardon her later. A little less than a year and a half remains in President Obama’s term. Pardoning Clinton would be a fitting capstone to his presidency. If he doesn’t do it, though, Hillary still has options. There’s always President Trump.