James Downie is The Post’s digital opinions editor.

Father Daniel Berrigan died Saturday at 94. The longtime peace activist gained national attention in 1968 when he and eight others, including his brother Philip (also a priest), burned draft records taken from a Selective Service office in Maryland. Decades later, he remains a powerful example of a man who never wavered in his beliefs, standing up time and again for the poor and oppressed. In his last years, Berrigan no longer had the energy to protest as frequently. But if he had been a few generations younger, can there be any doubt that he would have been at forefront of those protesting the expansion of the drone war under President Obama?

There have long been policy, constitutional and moral questions about the drone program — all made more difficult to answer by the Obama administration’s refusal to even acknowledge the program until 2013. As Obama’s presidency comes to an end, we have stunning new details about how the program works — first released in October on the Intercept website, now updated and collected in the book “The Assassination Complex” by Jeremy Scahill and Intercept staffers. “The Assassination Complex” is in large part built around the revelations of an anonymous whistleblower who leaked documents about U.S. use of drones in Somalia, Libya and Afghanistan from 2011 to 2013. What he or she reveals further confirms the practical, legal and moral failings of Obama’s expanded drone war.

For starters, although drones may be quite good at killing people (even if not always the intended targets), it’s not clear that they are an effective tool in the war on terrorism. Obama’s embrace of drones has led to a preference for killing rather than capturing terrorists. The documents include a study from the Defense Department’s Intelligence, Surveillance, and Reconnaissance (ISR) Task Force, which concluded that “kill operations significantly reduce the intelligence available from detainees and captured material.” And as retired Gen. Michael Flynn, former head of the Defense Intelligence Agency, said last year, “When you drop a bomb from a drone . . . you are going to cause more damage than you are going to cause good,” including more radicalized terrorists.

Then there are the legal and constitutional questions. The leaked documents show the disturbing ease with which an innocent civilian — American or not — can be added to the U.S. government’s main terrorist database, such as on the basis of a single “uncorroborated” Facebook or Twitter post. In a 2014 court filing, the government admitted that 469,000 people had been nominated in 2013 for inclusion in an additional government database of “known or suspected terrorists.” Only 4,900 were rejected. Presumption of innocence this is not. And although Osama bin Laden’s name was in a terrorist database long before he was killed, so too was the name Abdulrahman al-Awlaki — innocent, 16 years old, an American citizen and killed by a U.S. drone strike.

Furthermore, it’s clear from the documents that the White House has overstated the prudence with which it undertakes strikes. In May 2013, Obama said that strikes would be conducted only against those who were a “continuing and imminent threat to the American people” and only if there were “near certainty” that there would be no civilian casualties. But the documents show that when the president approves a strike on an individual, the Pentagon and CIA (both of which conduct strikes) have a 60-day window to act. You don’t need a dictionary to know that 60 days is not “imminent.” And the ISR study says that the standard for drone strikes is not “no civilian casualties,” only that it must be a “low” collateral damage estimate.

Nearly eight years later, Obama’s decision to expand the drone war has led to the deaths of hundreds of civilians, according to the Bureau of Investigative Journalism, a disturbing expansion of presidential power and harm to the country’s ability to fight terrorism.

What makes Obama’s policy even more disappointing is that whoever succeeds him will likely widen the program further. Obama at least gives the impression of taking the constitutional and moral consequences of the drone program seriously, even if this has been only a small restraint on the program. But Hillary Clinton has stoutly defended the drone program inside the White House as secretary of state, afterward in her memoir and on the campaign trail. Given her hawkishness compared with Obama, it seems likely that the program would only grow under her. And Donald Trump? Well, he has already promised to commit war crimes.

I have little doubt that Obama chose to rapidly expand the drone war under the sincere belief that it was legal, moral and good policy. But that belief was mistaken; the drone war is an indelible legacy — and shame — of his presidency.