DAVID GREENE, HOST:
And let's bring in a well-known voice from the Democratic Party. It is Senator Barbara Boxer of California. She is backing Hillary Clinton to be the Democratic nominee. Senator Boxer, good morning.
BARBARA BOXER: Good morning to you.
GREENE: So why has Hillary Clinton had a harder time locking up this nomination than many people expected?
BOXER: Oh, she's doing so well. Anyone who knows Democrats as I do knows that we are a raucous bunch and we do have a big umbrella. We go from left to left of center. So I think what's happening as we go along here is that Hillary is becoming a unifying force. I think that's what we learned last night when we saw the results. And Bernie has made a positive contribution to the dialogue. There's no doubt about it.
GREENE: What do you see as that contribution?
BOXER: The issues, his passion, his fervor, his bringing some new people into the race - you know, I've run 24 times if you count my primaries and my general elections...
GREENE: You've been in a few campaigns.
BOXER: Yeah. I lost the first one - very hard to lose, I admit. But I will say this. You know, the primaries make you stronger. They make you tougher. They make you hone in on your message. They make you work hard. And people see in a contested primary what it has taken for Hillary, who, because she's been around and working for so many years in the public eye, and because she had every Republican beating up on her, and then Bernie in his sweet way doing the same, people saw, she's got what it takes.
GREENE: Well, senator, if I could just ask you about a specific issue. We had Congresswoman Tulsi Gabbard on the line - your Democratic colleague from Hawaii. I mean, she's a war veteran. She has endorsed Bernie Sanders. And she said one reason is she feels like Hillary Clinton favors intervention too much. She brought up Iraq; she brought up Libya. Now, you opposed the Iraq War. Hillary Clinton supported it. Is that not an issue for you that sort of lingers?
BOXER: No. It does not. And I'll tell you the reason. Hillary Clinton said the words that are the toughest, toughest for any politician - I made a mistake. And I'd rather have someone who really learned from their mistake, who sees that, you know, military force is a last resort. And if you hear her you can truly hear that she has learned that lesson. So does everybody make mistakes? Absolutely. But I've never seen a candidate in my lifetime so ready to lead as Hillary. And I would say, if you listen to her words last night, how she talked about making America whole - what does that mean? It means fighting for everyone. We can't just paint any group with a broad brush. We go after the bad guys, but we need to work together and, as she said, build ladders of opportunity.
GREENE: But if...
BOXER: I think that's what's happening here.
GREENE: If I may, do you...
BOXER: On foreign-policy - I was there. I know. I was in the minority.
GREENE: But do you blame Democratic voters who might have some doubts because of that vote and feeling she's too interventionist?
BOXER: Well, they can have doubts. That's a healthy thing. She needs to win them over. Nobody is perfect, otherwise each of us would get 100 percent when we ran. Every time I ran, I lost Democratic votes. They didn't like my view on choice or they didn't like my view voting no on the war. Nobody is perfect. The question is, who has the gravitas? Who has the experience? Who has the common sense? And frankly, in this election, who is sane? I mean, these Republicans are - they make kids fighting in a schoolyard look good.
GREENE: We just have about 15 seconds left.
BOXER: Sure.
GREENE: You came into the Senate at a time when it was very significant - there were a lot of women elected. Is this nomination personally important for you?
BOXER: It is very important on issues and on the fact that Hillary would make history as we get to celebrate the 100th year of our right to vote as women.
GREENE: All right, that is California Senator Barbara Boxer. Senator Boxer, thanks as always for talking to us. We really appreciate it.
BOXER: Thank you. Transcript provided by NPR, Copyright NPR.