The following is a transcript of an interview with Senator Amy Klobuchar that aired Sunday, December 22, 2019, on "Face the Nation."

MARGARET BRENNAN: You know, we're coming up on a presidential election year when Saturday Night Live starts their show with a primary debate. Right now the real Senator Amy Klobuchar joins us from Council Bluffs, Iowa. Good morning to you, Senator.

SENATOR AMY KLOBUCHAR: Good morning, MARGARET. I think Rachel Dratch does a pretty good job of playing me, I enjoy it.

MARGARET BRENNAN: Well, you came out swinging at this last debate. You got a lot of attention. Do you think this is a more aggressive but still moderate Amy Klobuchar?

SEN. KLOBUCHAR: I have been the same since the very beginning when I announced my candidacy in the middle of that blizzard in the Mississippi River. I think it's really clear we need someone leading this ticket who's going to bring people with them instead of shutting them out. And the point I made in the debate is that I've been consistent in my views. I have passed over 100 bills in the United States Senate during a really difficult time. And I have won in the reddest of red districts and won with suburban and rural voters and Republicans and independents and a fired up Democratic base. I think that's a good case to be made. And I think the other thing I did in this debate was just make the case of how I want to be the one debating Donald Trump.

MARGARET BRENNAN: Right.

SEN. KLOBUCHAR: You know, he started his life with a four hundred thirteen million dollar gifts that he got through his career from his dad. I started when my grandpa worked underground in the iron ore mines and saved money in a coffee can to send my dad to a two year community college. And when you're given that gift of opportunity, you don't go into the world with a sense of entitlement like Donald Trump. You go into it with a sense of obligation to lift other people up instead of cutting them down instead of hoarding it for yourself. And that's a point that I've been making all through Iowa. And I think it is more than just the nitty gritty of policy. It's also a value statement because so many people want a values check on this president. They want someone who gives them a decency check, a patriotism check.

MARGARET BRENNAN: Well, and there is the very real check that you as a senator may have to deliver in this impending Senate trial to continue the impeachment process. But you've said your campaign's not going to get in the way of your job as a senator. You can't be in two places at once, though. And Iowa is really make it or break it. How is the impeachment trial going to impact your campaign?

SEN. KLOBUCHAR: Well, look at what I've just done. I finished that L.A. debate. We had a little after party, got up at 4:00 a.m., did the shows, got to Iowa, went on a bus tour. And we've already done fifteen counties in a day and a half, ending last night at midnight. And had record crowds at every little town that we went to. That's how I'm gonna do it. I don't need a lot of sleep. I work really hard. And I also have endorsements of more electeds and former electeds than anyone in this race, in this primary field. So we're gonna have- in the state of Iowa, so we are going to have so many people showing up to help me if I'm doing my constitutional duty, which comes first as a U.S. senator. And my husband was just in Nevada. My daughter, I've got the governor and lieutenant governor of Minnesota. Everyone's volunteered to help out because they get that we're going to need some help and I'll have to Skype in for town hall meetings. There is modern technology.

MARGARET BRENNAN: Yeah.

SEN. KLOBUCHAR: I think we're gonna find a way to do this.

MARGARET BRENNAN: Well, Skyping in for a campaign, that's- that's an interesting choice because of what you're juggling here. But is- is your campaign going to ask the DNC to reschedule the upcoming debate? It could fall right in the middle of that trial.

SEN. KLOBUCHAR: Well, my first belief is we have to have the debate. And if for some reason it doesn't work, sometimes there's breaks in the trial and even when you looked at past impeachment trials, there were breaks in the day so we could get there. If that day doesn't work, there's plenty of other days. We know we don't have Sundays when we're doing this and there's going to be other days after that. We may just have to have the debate closer to the Iowa caucuses. But we have to have an Iowa debate--

MARGARET BRENNAN: Is that being discussed right now?

SEN. KLOBUCHAR: I don't know, I have made it very clear that there should be no excuses. I'm ready to debate at midnight if that's what we have to do. We have to have a debate before the Iowa caucuses. That would be to my advantage if it was at midnight. I'd be happy.

MARGARET BRENNAN: Well, Senator Schumer has asked Leader McConnell to allow witnesses at this upcoming trial. And we know the decision on what the- the outlines of this are going to look like are still an open question. How do Democrats force witnesses to be allowed, people like Mick Mulvaney and Secretary of State Pompeo?

SEN. KLOBUCHAR: Well, some of this is going on right now where Speaker Pelosi is trying to get some sense from the majority leader of the Senate, Mitch McConnell, about what's happening, and I know Senator Schumer had a meeting with him. I'm not sure it went that well. But in the end, Mitch McConnell is going to think about it over the holidays. Look at what we're dealing with. I couldn't believe the number of people that came up to me about this. First, they were focused, of course, on the investigation and the impeachment, but now they're saying, why wouldn't we have witnesses at a trial? You know, they're thinking like law and order. The first half, there's an investigation and then you have a trial. And if the president is so innocent and claims he's innocent, why would he not allow, just like Richard Nixon did, the people that were closest to him to testify? And I think we have some--

MARGARET BRENNAN: Is- is that the--

SEN. KLOBUCHAR: --pretty shocking news, MARGARET.

MARGARET BRENNAN: Is that the Democratic strategy to take these two weeks of break, to put pressure on the Republican caucus to- to back away and allow witnesses?

SEN. KLOBUCHAR: I think it- it's not a strategy. It is a fact. It is a, "you can't have a trial if you don't have the key witnesses. You can at least have a thorough trial." Look at what we just learned on Friday from a document request. And that's- it's this guy named Michael Duffy, who worked for Mick Mulvaney over at OMB. He's the one that sent the email to a bunch of people and said to withhold the aid to Ukraine. He sent this email, I have it in my hand, 90 minutes after the president of the United States talked to president of Ukraine. And this is what he says. He says, "given the sensitive nature of the request. I appreciate your keeping the information closely held to those who need to know." What does that mean? What a great question. That's a question I want to have answered.

MARGARET BRENNAN: Well the way- aid was on hold--

SEN. KLOBUCHAR: So if you don't allow--

MARGARET BRENNAN: --before that date, though. What do you think that shows you?

SEN. KLOBUCHAR: But the point is, why did he send this email just 90 minutes after the president made this call? Why would this email go? So this is the kind of information that we need to get out, because there's a story on this, front page New York Times today. And I just found out about this over the last few days. But mainly it's Bolton and Mulvaney, this guy Duffy, and one other person. It's not like we're going on some kind of fishing expedition. We just want these major witnesses.

MARGARET BRENNAN: Yeah.

SEN. KLOBUCHAR: If the president is so innocent and shouldn't be impeached, why is he afraid to have these people come forward? That's what people are asking me when I'm at these town hall meetings.

MARGARET BRENNAN: All right. Senator Klobuchar, thank you. And we'll be right back with a lot more FACE THE NATION. Stay with us.