GWEN IFILL: The Republican field grew more crowded, as two more contenders jumped into the race for president today, and yet another announcement is expected tomorrow.

It's Politics Monday, so we will talk it all through with Amy Walter of The Cook Political Report, and Tamara Keith of NPR, who's on the campaign trail in Las Vegas tonight.

Let's start off, ladies, by listening to both the two new candidates, just a bit of what they had to say today.

CARLY FIORINA, Former CEO, Hewlett-Packard: If you're tired of the sound bites, the vitriol, the pettiness, the egos, the corruption, if you believe that it's time to declare the end of identity politics, if you believe that it's time to declare the end of lowered expectations, if you believe that it's time for citizens to stand up to the political class and say enough, then join us. It's time for us to empower our citizens, to give them a voice in our government.

BEN CARSON, Former Neurosurgeon: I'm not politically correct and I'm probably never…

BEN CARSON: I'm probably never going to be politically correct, because I'm not a politician. I don't want to be a politician because…

BEN CARSON: … politicians do what is political expedient. And I want to do what's right.

GWEN IFILL: Amy, Ben Carson got on stage in Detroit with his — introduced his wife, his kids, his entire campaign staff, it looked like, and said, I'm not a politician, but I'm going to run for president for the next almost more than a year.

AMY WALTER, The Cook Political Report: Yes. That's right.

He is running, and Carly Fiorina as well, as the outsiders. These are two people who do not have elected experience and they think that this is the perfect time to run for president with somebody without elected experience, given how frustrated Americans are with what's happening in Washington with the political calculations that are going on in Washington.

They're going to try to make that the centerpiece of their campaign. And you saw it with both of them. They talked about crony capitalism. They talked about being politically incorrect, saying things that politicians won't say. Maybe they will get a little bit of traction. The reason they will get a little bit of traction? They certainly stand out in the field, right, the only African-American candidate and the only female candidate.

GWEN IFILL: It's actually turning into a pretty diverse field.

Tamara, let's talk a little bit about what you thought about Ben Carson's rollout today. He came — for some people, he's coming out of nowhere, but he's gotten very popular.

TAMARA KEITH, NPR: Absolutely.

He really came to prominence the first time because he's this neurosurgeon who worked at Johns Hopkins University. He wrote a book that was turned into a movie starring Cuba Gooding Jr., who played him. Then, in 2013, he spoke at the National Prayer Breakfast, stood at a podium a few feet away from President Obama, and trashed Obamacare, said a lot of those politically incorrect things that he's become known for, and that made him something of a conservative darling.

And he did the talk show circuit. People have — as he said, people have been asking him to run for president. He said he never dreamed of running for president, but people keep asking him to. There was a recruit Ben Carson effort that raised more than $10 million. Now, much of that was then spent on fund-raising, so it just sort of cycled through, but people were asking him to do it.

GWEN IFILL: I want to ask you, Amy, a little bit about Carly Fiorina. People are asking him to run. There's no question. Who's asking her to run?

AMY WALTER: I think she's asking herself to run and she's hoping that, again, she can set herself up as somebody who is not part of the established system.

Now, unlike Ben Carson, who hasn't run for anything, city council, state senate, nothing, she has run one time, lost to Barbara Boxer in the United States Senate race in 2010 in California. But she's still trying to present herself as somebody who has had a different set of experiences.

She's a corporate titan, of course. She ran Hewlett-Packard.

GWEN IFILL: Which didn't end so well.

AMY WALTER: Didn't really end very well.

And what Barbara Boxer talked about a lot and attacked her about a lot on the campaign trail in 2010, how many layoffs there were at Hewlett-Packard under Carly Fiorina's stewardship. So that is going to get certainly a lot of attention as the economy is a big, big issue.

GWEN IFILL: Tamara, you're in Las Vegas covering Hillary Clinton tonight. So, it seems that the is what Carly Fiorina wants to be the person to position herself as the only other woman in the race so far to run against Hillary Clinton.

TAMARA KEITH: Absolutely. Right out of the box, her announcement video features Hillary Clinton's announcement video, saying, I'm about to do this thing, and then Carly Fiorina clicks the remote control and says, we need to get rid of these career politicians.

So she is really positioning herself as the anti-Hillary. When she's spoken at these various Republican cattle calls and other events, she is pretty firmly, viciously attacking Hillary Clinton, in a way that she can because she's a female candidate. And people in the audiences at these events have been really fired up about that. And so that's the route she's taking, is that she's going to be the attack dog in the field against Hillary Clinton.

GWEN IFILL: Let me ask you all to race ahead a little bit to tomorrow, because you won't be here tomorrow, so I have to ask you this today. Mike Huckabee is also getting into the race. And we — you talk about people who have run before. He certainly has, Amy.

AMY WALTER: He ran before. And there was a very low bar for him when he first ran in 2008. He ended up surprising everybody, winning Iowa, becoming a nationally known candidate, and then of course sort of faltering and petering out.

Since then, he went on to go and have a stint on FOX as a host. He's coming back now as a politician, saying that he brings a different set of perspectives into this race. When he ran last time, he was the evangelical candidate. He's trying to run now as an evangelical candidate, but also on his blue-collar roots, right?He talks about sort of a populist message when he was governor of Arkansas.

And, like Carly Fiorina, he talks about the fact that he's taken on the Clintons. He's from Hope, Arkansas, like Bill Clinton is from Hope, Arkansas. In his announcement video, he talked about taking on the Clinton machine and that is what he wants to use as his claim.

GWEN IFILL: Tamara, is there room in the Republican field as it's now organizing itself for someone to be — where is he, in the right, in the left of the field, and especially for fund-raising?

TAMARA KEITH: Yes, I think that he has sort of a challenge, in that he used to be the evangelical, but in this race, there are at least three people angling for that evangelical vote, probably four.

Ted Cruz is angling for it. Rick Santorum, if he gets in, is going for it. Scott Walker is trying for that group as well. So Mike Huckabee has a much narrower lane this time. He also has a lot of Republicans who think that he's not a fiscal conservative, who are not happy with his record as governor in Arkansas, and so he has a lot to navigate.

GWEN IFILL: And let's talk about the Clintons for a while before we run out of time here, because Hillary Clinton now has Bernie Sanders, an actual official person who is challenging her, but she also has some things she's trying to clean up.

She said today that she is going to testify about Benghazi, she is going to testify about her e-mails, one time only, one time only. And then her husband was in Africa with the Clinton Foundation explaining what the Clinton Foundation situation, kind of mansplaining it. How is that going…

AMY WALTER: Yes.

It seems that there's a real Hillary Clinton opponent right now, Bernie Sanders. And then there's the other Hillary Clinton opponent, which is Hillary Clinton and the Clinton Foundation. And I don't think that is going away any time soon. It just seems every day we have another story about where this money is coming from, who spent it, was it recorded and was it properly given over to the State Department?

So, lots of questions still swirling about that, but bottom line, there is a big vacuum around the Democratic nomination. Hillary Clinton is not — she's on the campaign trail, not doing all that much talking. The vacuum is getting filled with this stuff.

GWEN IFILL: That's a good point, Tamara. You're out there on the campaign trail, but now her husband has given one more interview than she has, which is to say one since this campaign got under way.

TAMARA KEITH: Yes.

GWEN IFILL: What do you expect? Do you expect her to be in the position where she has to answer those kinds of questions out there in Nevada?

TAMARA KEITH: It's not clear that we're going to have the access to shout those questions to her as she's doing another one of these small roundtable events, this time at a high school, where she will be meeting with students to talk about fixing the broken immigration system, as they have described it.

That's not a great place to answer questions about the Benghazi committee or about her husband's somewhat tone-deaf remarks in Africa. He said that they need to pay the bills. That's what you call an unforced error.

GWEN IFILL: OK. Well, we will be watching for the forced and the unforced.

Tamara Keith, Amy Walter, thank you both very much.

TAMARA KEITH: Thanks.

GWEN IFILL: For more on what these candidates for president are bringing to the campaign, you can check out our online feature, What They Believe. That's on our Politics page at PBS.org/NewsHour.