With Barack Obama's presidential term winding down, there's a renewed push to convince the president that he should pardon Edward Snowden, the former NSA contractor who leaked classified details about the U.S. government's surveillance programs.

This campaign comes, coincidentally, with the release of a new Oliver Stone film — a largely glowing portrayal of the fugitive — and a damning U.S. House Intelligence Committee report about his activities.

Three major human rights agencies — Amnesty International, Human Rights Watch and the American Civil Liberties Association — recently joined together to launch the pardonsnowden.org campaign, calling on Obama to pardon Snowden, who is currently living in Moscow, "and let him come home with dignity."

'Should be hailed as a hero'

"Snowden should be hailed as a hero. Instead, he is exiled in Moscow, and faces decades in prison under World War One-era charges that treat him like a spy," a message on the website states. "Ed stood up for us, and it's time for us to stand up for him."

Dinah PoKempner, left, general counsel for Human Rights Watch, listens as Edward Snowden speaks via video link from Moscow during a news conference to call upon Obama to pardon Snowden before he leaves office. (Mary Altaffer/Associated Press)

The campaign's supporters include actors Daniel Radcliffe and John Cusack, professor Noam Chomsky, Apple co-founder Steve Wozniak, musician Peter Gabriel and billionaire George Soros.

"I think we owe Mr. Snowden a huge debt of gratitude, because if it wasn't for him, we would never become aware of the massive scale of surveillance taking place by government intelligence agencies," said former Ontario privacy commissioner Ann Cavoukian, who also signed her name to the pardonsnowden.org campaign.

Yet, despite this renewed interest and all the high-profile support, it seems highly unlikely that Obama will grant any kind of clemency to Snowden.

"Despite the current media focus on Snowden's case, the president hasn't given any indication that he's seriously considering it," said Jeffrey Crouch, an American politics professor at American University and author of The President and the Pardon Power: A Bibliographic Essay. "Obama has scrupulously avoided pardoning high-profile offenders. A Snowden pardon may indeed happen one day, but I doubt that this president is eager to be the person to grant it."

A polarizing figure, Snowden has been hailed as a courageous whistleblower by his supporters. But his detractors have branded him a criminal and traitor whose leaks, they believe, compromised U.S. security.

The White House has given no indication it's ready to offer Snowden a pardon, and has repeatedly said that Snowden's conduct put American lives at risk, and that he needs to return to the U.S. to face the charges against him.

According to the House Intelligence Committee three-page summary, Snowden, in June 2013, absconded with 1.5 million documents, perpetrating "the largest and most damaging public release of classified information in U.S. intelligence history."

Thousands of those documents, which were subsequently leaked to journalists, revealed massive domestic surveillance programs, including the collection and storage of U.S. landline calling records — times, dates and numbers but not content of the calls.

Critics of Snowden, including the committee, argue that most of the documents he took had nothing to do with domestic surveillance but instead related to military, defence and intelligence programs — information that could be used by U.S. enemies.

Faces 30 years in prison

​Snowden has been charged with theft of government property, unauthorized communication of national defence information and wilful communication of classified communications intelligence information to an unauthorized person. If found guilty, Snowden could face 30 years in prison.

P.S. Ruckman, a political science professor and editor of the Pardon Power blog, said an important clue into whether Obama would pardon Snowden is the president's general record on clemency.

"That's the telling factor here," Ruckman said. "And I tell you what — if you're asking for a pardon from this guy, he's pardoned fewer people than any president since John Adams."

Obama has so far pardoned 70 people. Compare that to other relatively recent two-term presidents: George W. Bush (189) and Bill Clinton (396).

In a news conference at the Pentagon last month, Obama said that by the end of his term his pardon record would be "roughly in line with what other presidents have done."

Snowden was a contractor for the National Security Agency. He stole over 1.5 million documents and subsequently leaked thousands of files, exposing massive domestic surveillance programs being conducted by the agency. (Patrick Semansky/Associated Press)

During his presidency, Obama has instead focused on commuting sentences, mostly for non-violent drug offenders. (The White House, on its website, indeed boasts that Obama has commuted more sentences than the previous 10 presidents combined.).

"No one's expecting some waterfall of pardons, much less controversial pardons," said Ruckman. "I mean, no way, I just don't see that happening."

'Would poison the well'

Most of the sentences Obama commutes are below the radar, but the potential for controversy is still there, Ruckman said.

Obama wants to continue with his commutations but "he doesn't want to screw it up by throwing in a Snowden pardon. It would poison the well," Ruckman said.

A president has the power to pardon anyone accused of federal criminal acts (with the exception of someone who has been impeached) for any reason, or no reason at all. The pardon can also be applied before a case, during a case or after conviction.

Seeking a pardon is a complicated and bureaucratic process. An individual would apply to the Office of the Pardon Attorney, who then contacts the judge and prosecuting attorney related to the case. The application then goes to the FBI for a background check, back to the pardon attorney, who then makes a recommendation to the deputy attorney general. Then a recommendation is made to the White House counsel before it ends up on the president's desk.

President Barack Obama has so far pardoned 70 people, focusing instead on commuting the sentences on non-violent drug offenders. (Carolyn Kaster/Associated Press)

But for a high-profile case like Snowden's, the pardon attorney may not even be consulted, according to one former U.S. pardon attorney.

"That kind of a case, a foreign policy case ... traditionally those are handled elsewhere in the Department of Justice," Margaret Love said.

Ruckman said Snowden doesn't seem to be offering anything too substantial to justify a pardon, like information he may have obtained while in Russia. Instead, his case rests on his belief that his intentions were noble.

"I think if you're the president and the Department of Justice, if anything, you're going to say 'What do you have to give us? If you have something to give us then we can talk turkey.'"

But Cavoukian said she's holding out hope that Obama, possibly on the last day of his presidency, will issue Snowden a pardon.

"I'm just praying for this outcome — but the odds are against me."