Updated

This is a rush transcript from "On the Record," March 10, 2016. This copy may not be in its final form and may be updated.

GRETA VAN SUSTEREN, FOX NEWS HOST: Former 2016 GOP presidential candidate Carly Fiorina is already back in the game. And she is endorsing her one-time opponent and Carly Fiorina goes ON THE RECORD.

So, I will let you tell us who you're endorsing, but it was yesterday and we know who it is. But tell us.

CARLY FIORINA, FORMER 2016 GOP PRESIDENTIAL CANDIDATE: Well, you know, I endorsed Ted Cruz. I was very proud and please pleased to do so. And I came to that conclusion actually before I ever sat down and had a meeting with him about that endorsement. I came to that conclusion when I stood in the voting booth during the Virginia primary. Saw my own name on the ballot which was kind of a thrill. But thought long and hard about why I had ran for president.

And I ran because I thought we need someone to challenge the system and a real constitutional conservative, and Ted Cruz will challenge the system. He has challenged the system. And we know, for example, the kind of Supreme Court justices he will nominate and that matters a lot right now.

VAN SUSTEREN: Carly, I'm going to do to you what I did to Governor Chris Christie when he dropped out of the race and endorsed Donald Trump. Here's what you told me in January about Senator Ted Cruz.

(BEGIN VIDEO CLIP)

FIORINA: My issue is that I think both Donald Trump and Ted Cruz are far too divisive as candidates to ever beat Hillary Clinton. And I also don't think you can win when you have someone like Senator Cruz who says one thing in the drawing rooms of Manhattan and another thing in the living rooms of Iowa. That's kind of what politicians do. They say what they need to say to get elected and then they do whatever they please.

(END VIDEO CLIP)

VAN SUSTEREN: Carly, what happened between January and now? Because he was divisive in January and saying two different things in Manhattan and Iowa and you are standing behind him?

FIORINA: Yes, well, look, Greta, I understand this game. In January, lots of things were different. Lots of things were different. Here we are --

VAN SUSTEREN: It's not a game. Wait a second, Carly.

(CROSSTALK)

FIORINA: Our choices, wait a second, no. Our choices have narrowed dramatically. Ted Cruz is the only guy who can beat Donald Trump.

We need to beat Donald Trump because I'll tell you what -- Donald Trump is not a conservative. Donald Trump will not challenge the system. He is the system. He has benefited from the system.

I will tell you who most definitely cannot beat Hillary Clinton is Donald Trump, because he and Hillary Clinton are two sides of the same coin. They're two peas in a pod.

So, I'm endorsing Ted Cruz because we do have to unify the party now. And I hope that my endorsement will serve as a signal to others that it is time for choosing.

VAN SUSTEREN: Are you saying --

FIORINA: It is time for choosing and Ted Cruz is my choice.

VAN SUSTEREN: Are you saying he is less bad than Donald Trump in your mind?

FIORINA: Oh, I think they are totally different people. Ted Cruz is actually a constitutional conservative. How do I know that? Because he has argued in front of the Supreme Court nine times to protect our rights and liberties as enshrined in Constitution.

Donald Trump, for example, thinks nothing about saying, I'm going to change the libel laws to hold the press accountable. Wow, that's not exactly First Amendment. Ted Cruz has challenged the system. And he has the enemies to prove it. As someone who has challenged the status quo all my life I know when you do that you make enemies.

Donald Trump has never challenged the system. He has used the system. He has used the system to benefit himself.

Here is what I also know the more contests that go on the more clear it becomes that Donald Trump support among those have haven't made up their mind is falling and not rising. Ted Cruz's support is rising. In other words, he is beginning to unify the party.

VAN SUSTEREN: Carly, always nice t o see you and good luck with your candidate and have fun tonight at the debate.

FIORINA: Thanks so much, Greta.