GWEN IFILL: In a vote on the Senate floor last night, lawmakers blocked a bill that would have drastically changed the way the National Security Agency currently monitors American citizens.

MAN: On this vote, the yeas are 58, the nays are 42.

GWEN IFILL: With that, the USA Freedom Act effectively died on the Senate floor last night, failing to garner the 60 votes needed to move to full debate.

The legislation would have ended the National Security Agency's bulk collection of domestic phone call records, so-called metadata.

SEN. PATRICK LEAHY, (D) Vermont, Chair, Judiciary Committee: Our bill protects Americans.

GWEN IFILL: The lead sponsor, Vermont Senator Patrick Leahy, spoke for most of his fellow Democrats.

SEN. PATRICK LEAHY: The USA Freedom Act provides for commonsense reforms to government surveillance. It promotes greater accountability and transparency of the government's surveillance programs.

GWEN IFILL: Former NSA employee Edward Snowden revealed the secret bulk collection program last year. It was authorized under Section 215 of the Patriot Act. This new bill would have forced the agency to get court orders for specific data from telecom companies. Most Republicans opposed the measure.

Georgia's Saxby Chambliss, ranking member on the Senate Intelligence Committee, called it totally flawed.

SEN. SAXBY CHAMBLISS, (R) Georgia: But the fact is, there cannot be one single case pointed to by anybody who can show that as a result of the collection of metadata under 215, any American has had their privacy rights breached. It simply has not happened. It will not happen if we keep this program in place.

GWEN IFILL: President Obama had proposed curbing the NSA's data gathering, and the House approved its own weaker version of the bill in may. The White House supported the Senate version, in part because the law authorizing the entire program expires next June.

Joining me now to discuss what comes next for NSA reform in Congress is Democratic Senator from Vermont Patrick Leahy. Leahy, who is chairman of the Senate Intelligence Committee, co-sponsored the legislation that failed last night.

We reached out to several Republicans who opposed the bill who were not available to us tonight.

Senator, part of the debate last night was whether your solution to this issue went too far or didn't go far enough. Where did it land?

SEN. PATRICK LEAHY: Well, we got 58 votes out of 100 senators. Normally, that would be enough to pass a bill, but the Republican leader wanted it filibustered and wanted it blocked, didn't want to have amendments, didn't want to go forward.

And he was able to keep most of the members of his caucus with him to do it. I think that's a mistake. We all know there's got to be changes in the NSA program. We all know there's going to have to be changes in these intelligence programs. We had a good compromise, one the House of Representatives would have accepted.

Let's go forward with it. Let's do it, because, next year, everything expires anyway.

GWEN IFILL: Well, I definitely want to ask you about that, but let's talk about what your bill would have done first.

How would it have — how would have ending — how would ending bulk collection have protected American citizens?

SEN. PATRICK LEAHY: Because, right now, we collect everything and we actually get nothing, except that we go into everybody's life, yours, mine, everybody else's.

That's not what we believe in as Americans. We should have something that is very specific, that actually relates to threats, and then has some very clear understandings of who can be looked at. For one thing, we had somebody who could raise an issue in the secret courts and say, wait a minute. You're going too far. Let's take this up on appeal.

We had a lot more checks and balances. That doesn't make us less safe, but it does make the average American a lot more secure in their privacy.

GWEN IFILL: How would — how would streamlining or in other ways changing the federal surveillance court, the secret court you referenced, how would that have changed things?

SEN. PATRICK LEAHY: Right now, there's no appeal. If the court says, OK, another the government's right, even though they may be basically by their actions ruining someone's business or reputation or closing down their business, nobody can say anything. Nobody can even talk about it.

What we would do is have somebody in there as a public advocate who could say, you're going too far. You have got the wrong person. We're going to take this up on appeal. A lot of people, a lot of people say we ought to at least have that.

There's no other court in this country where you don't have at least an ability to have some kind of an adversary or have another voice heard. There's no other court in this country that does that. And I think a lot of people who have spent a lot of time in courtrooms, as I have, are concerned about that.

GWEN IFILL: Well, as you alluded to a moment ago, the legal authority for this program is going to expire in June unless something else happens. what happens if that occurs?

SEN. PATRICK LEAHY: Well, if that occurs, then just about everything NSA does and everything that they do in these secret courts are going to end, because everything in the Patriot Act will end.

I think that there are some things that we should be allowed to do, that we need to do for our security, but not at the cost of individual liberties. If this was a — you know, we have a case where you have Mike Lee and Ted Cruz, me, Chuck Schumer. We're going across the political spectrum.

We came together on this. And I think that many people, certainly our high-tech companies who are being battered about around the world because of our laws, they would have loved to have seen this pass. And I think there's a lot of disappointment today that the Republican leader stopped a good bipartisan bill from going forward.

GWEN IFILL: And, yet, privacy advocates say that even if your — what you describe as a good bipartisan bill had gone forward, it still would have left the most damaging, the most troubling parts of the law untouched.

SEN. PATRICK LEAHY: No, actually, we had a lot of privacy experts who were very strongly in favor of it.

We had the ACLU, for example, in favor of it. We also had the NRA in favor of it. We had quite a coalition. We had almost every one of the high-tech companies that deal in sharing information, they were in favor of it. It was much — it was far more protective of privacy than what we have now.

And I think that unless we pass a bill similarly to what I have or even more protective of privacy than what I had proposed, we could very well end up in this country not having any law one way or the other.

GWEN IFILL: Well, how will the — how can that happen if the Republicans take over with their 60-vote majority in January?

SEN. PATRICK LEAHY: Well, they're not going to have a 60-vote majority.

And they have to pass something by June 1. There are a lot of people, both on the Republican side and on the Democratic side, who are very upset that the Republican leader refused to allow votes up or down, refused to allow amendments to come forward. And they're not going to be very eager to cooperate in getting that 60 votes that they will need in June.

GWEN IFILL: You're right. Best-case scenario, they will have 54 votes.

Senator Patrick Leahy, thank you very much.

SEN. PATRICK LEAHY: Good to be with you.