President Donald Trump’s unexpected announcement that he is mulling the pardon of legendary boxer Jack Johnson raises the obvious question: Why didn’t Barack Obama do it first?

After all, lawmakers and civil rights advocates have argued for years that Johnson’s conviction for violating the Mann Act was a clear example of a racist application of the law. Johnson’s real crime wasn’t the trafficking of women, it was dating white ones in an age when it was socially unacceptable for a black man to do so.

The campaign to grant Johnson a pardon began back in 2004 with high profile supporters, like Sens. Harry Reid (D-NV) and John McCain (R-AZ). But it really gained steam early in the Obama years, when the resolution passed through Congress in 2009.

And yet, Obama never acted, neither then, nor when the pardon push reemerged in 2013, nor during his last year in office when it re-emerged once more.

“It befuddled all of us,” said one congressional aide involved in the push. “We couldn’t for the life of us understand why he didn’t do anything or the administration didn’t.”

So what gives?

Gavin Parke, a former senior leadership staffer for Reid, said that his early impression was Obama didn’t want to act on Johnson out of political discomfort. “[R]eading between the lines,” he emailed The Daily Beast, “our conjecture was that they didn’t want to engage in divisive racial issues that were largely symbolic.” But the main reason that Obama held back, Parke added, was out of a rigid dedication to preserving norms. “The Obama White House was stringently opposed to the pardons process becoming politicized in any way. They felt so strongly about that, it may have extended even to posthumous pardons.”

Such a position seems, as one Obama veteran conceded, “quaint” in the Trump years. But it was a thing. As one senior official, who asked to speak on background not to characterize the president’s thinking, put it: “President Obama relied on the Department of Justice to make recommendations and it is against DOJ’s general policy to accept posthumous pardons.”

The general policy of the Department of Justice is, indeed, to not “accept for processing applications for posthumous pardons for federal convictions,” out of “belief that the time of the officials involved in the clemency process is better spent on the pardon and commutation requests of living persons.” And, indeed, when it formally weighed in on the Johnson matter in 2009, the DoJ specifically declined to make an exemption to that rule.

But the department did note that it was in Obama’s power to grant a pardon should he choose to do so. For that reason, another senior Obama official—who, for the same reasons, spoke on condition of anonymity—told The Daily Beast: “I doubt the issue was the posthumous granting.”

Other presidents, after all, have granted pardons to the dead, though admittedly rarely. As McClatchy reported, Bill Clinton granted one for Lt. Henry O. Flipper, the Army’s first African-American graduate of West Point, while Bush pardoned Charles Winters, an American businessman who transferred two B-17 aircraft to Israel.

When he was pressed on the matter in 2016, former Attorney General Eric Holder conceded that posthumous pardons are, in fact, given; but that they “are very rarely done.” He then offered a slightly more nuanced explanation as to why Obama never offered Johnson a pardon; mainly, that while Johnson was clearly a victim of racism, he also had some flaws.

“Jack Johnson,” said the man who’d been the nation’s top legal authority from 2007 to 2015, “no question was convicted unfairly. That might be a historical injustice that might need to be rethought.” However, he added, “there are on the other side, countervailing concerns about the way [Johnson] treated women, physically treated women. So all of this has to be balanced before this president or his successor would make a determination that a pardon is appropriate.”

Holder’s statement came toward the tail end of the Obama presidency, when Johnson’s advocates were making one last effort to convince the administration to act. By that point, the administration was making a full-on blitz to direct the presidential pardon and commutation powers toward those who were both still alive and enduring lengthy sentences for small-time drug offenses.

Trump has dropped that push entirely and used his pardon power sparingly. The first person he pardoned was disgraced ex-Sheriff Joe Arpaio. And it was reportedly done without going through the formal processes and channels that defined the Obama-era approach. When he announced that he was considering a full pardon for Johnson, Trump also revealed who gave him the idea to do so. It wasn’t McCain, who remains at home in Arizona, battling brain cancer. It was the actor, Sylvester Stallone.