Edward Snowden has described the Democratic presidential debate last month as marking an “extraordinary change”in attitudes towards him. In a lengthy interview with Sweden’s Dagens Nyheter published on Friday, Snowden said he had been encouraged by the debate between Hillary Clinton and Bernie Sanders, her main challenger for the Democratic nomination. During the televised encounter, both candidates called for Snowden to face trial , but Sanders said he thought the NSA whistleblower had “played a very important role in educating the American people”. That marked an important shift in the US debate over Snowden’s action, he said. The former National Security Agency analyst said it had taken 30 years for Daniel Ellsberg, who leaked the Pentagon Papers about the Vietnam war, to shift from being described regularly as a traitor. But not once in the debate had Snowden been referred to as a traitor. Snowden, who is living in exile in Moscow after leaking tens of thousands of secret documents from the NSA and its sister agency in the UK, GCHQ, said: “I did see the debate live. It was actually extraordinarily encouraging. In 2013, they were calling for me to be hanged. They were using the word ’traitor’ and things like ’blood on your hands’. Read more: Spying or security? British government presents new legislation to give authorities ‘licence to operate’ “Nobody on the stage, as far as I know, used the word traitor now. In just two years, that’s an extraordinary change." In the debate, Clinton said that Snowden had violated US law and should face trial. Sanders also suggested that he ought to be tried. “I think there should be a penalty to that,”he said. “But I think that education should be taken into consideration before the sentencing." Snowden, asked if he would vote, said he would definitely try, even if only as a symbolic gesture. “I’ll send them my vote by mail. It’s not like it will count in a meaningful way because such a small portion of the votes come by mail. But that’s not the point; the point is the expression of it,”he said. Snowden, who in the past supported the Republican Ron Paul, was asked if he would vote for Clinton or Donald Trump. He laughed, declining to comment on the grounds that it would be too inflammatory.