The National Security Agency wouldn’t confirm or deny Sen. Bernie Sanders’ (I-Vt.) query about whether the agency was spying on members of Congress, but also hasn’t answered his letter directly.

“NSA’s authorities to collect signals intelligence data include procedures that protect the privacy of U.S. persons. Such protections are built into and cut across the entire process. Members of Congress have the same privacy protections as all U.S. persons,” the NSA said in a statement.

Sanders said last night on CNN that he posed the question to NSA director Keith Alexander after receiving questions about the extent of surveillance activities.

“My initial thought was, of course not,” Sanders said of the question about whether Congress was spied upon. “But I thought about it, and I wasn’t sure what the answer was. And being unsure about whether or not the NSA is spying on members of Congress made me think that it’s imperative to get a flat, straight- out answer from these guys. What we do know, of course, is they have tapped the phones of foreign leaders around the world who are our allies.”

“Forty years ago , we had a president named Richard Nixon and he was prepared to do everything that he could to destroy his political opponents. And what I worry about is, if you have some other president like that or some rogue agent within the NSA, there’s just an extraordinary amount of information and power that they can have over Congress, blackmail members of Congress, not a good situation.”

Sanders said the NSA explanation that it only collects mass metadata yet doesn’t monitor phone calls suggests “that everybody at the NSA is and always will be wonderful, angelic, law-abiding human beings.”

“What happens if you have a rogue agent in the NSA? What happens if you have a president, somebody like a Nixon, who has no scruples at all and wants to destroy his political opponents, wants to know what’s going on in a political campaign, wants to hold a member of Congress, put him in a blackmail situation and leak information to a political opponent?” the senator said.

“I think one doesn’t have to be paranoid to be thinking that at some day in the future, that could happen. And I think when you have so much information being controlled by a secret agency, it is a real threat to American democracy.”

As far as NSA leaker Edward Snowden, Sanders said he wouldn’t support letting him off scot-free.

“My own belief is that I think, I would hope that the United States government could kind of negotiate some plea bargain with him, some form of clemency. I think it wouldn’t be a good idea or fair to him to have to spend his entire remaining life abroad, not being able to come back to his country,” he said. “So I would hope that there’s a price that he has to pay, but I hope it is not a long prison sentence or exile from his country.”