KING: A lot of questions raised and some very important lessons learned.

Let's begin our extensive breakdown of the big Republican debate with the Democratic perspective.

David Axelrod is President Obama's top campaign adviser. He joins us from New York today.

David, let's start with a simple question. What was your biggest lesson from the big Republican debate?

DAVID AXELROD, SENIOR OBAMA CAMPAIGN STRATEGIST: Well, I think that the tape that you just ran, John, was probably some of the most revealing that we have seen through these nine debates.

That one comment of Mitt Romney's in which he told the gardening service that he can't have illegals because he's running for office, not because it's wrong, not because it's illegal, but because he's running for office, I thought was a great insight into him.

And, you know, it helps explain why he can shift so easily from position to position on fundamental things, like health care, like choice and like gay rights and almost anything you can put your finger on. Last year, he attacked the president for being too tough on China. And now he's a trade warrior.

And you get the sense that everything is in service of running for office. And so no position or principle is to great to abrogate in service of that goal.

KING: We saw a very different Rick Perry last night. The governor of Texas had some flat -- I'm being kind -- debates leading up to this one. He was pretty feisty last night. But what did you learn about him?

AXELROD: Well, obviously, what's apparent is that he's going to try and fight for this. He's not going to go out with a whimper. And he was more challenging. I didn't learn a whole lot about his views.

I mean, his principal economic argument is that we can drill our way to prosperity. I think people understand it's more complicated than that. But the one thing you would learn from a political standpoint is that you know, he seems willing and eager to step up his pace in terms of Governor Romney and his pursuit of the nomination.

KING: If we look back at all the rules -- and we have both been through a lot of campaigns -- most of the rules, most of the history says, Herman Cain, there's no way he can do what he's doing. But he has jumped up.

Listen to this exchange.

(BEGIN VIDEO CLIP)

ROMNEY: Are you saying that the state sales tax will also go away?

CAIN: No, that's an apple.

ROMNEY: OK.

CAIN: We're replacing a bunch of oranges.

ROMNEY: OK.

(LAUGHTER)

ROMNEY: So, then Governor Perry was right that -- CAIN: No, he wasn't. He was mixing apples and oranges.

PERRY: I will bump plans with you, brother, and we'll see who has the best idea about how you get this country working again.

(END VIDEO CLIP)

KING: The 999 plan has helped Herman Cain go from nowhere to near the top of the national Republican polls. He's moving up in a lot of the key primary and caucus early battleground states. What is it about him or that plan that's captivating people?

AXELROD: Well, I think there are a couple of things.

What is it about him is that he's not a politician, at a time when politicians are trading very low. That's why Mitt Romney, who has been running for office for almost 20 years, keeps repeating, I'm not a politician, I'm a businessman.

I think running for office for 20 years probably characterizes you as a politician. But Cain's benefited from that. He's an engaging personality. But I do think that, as you move up, people begin to scrutinize you more closely, as they did last night.

And that tax plan is a very, very insidious thing for middle-class people, poor people in this country, essentially, as has been now reported, a tax increase on 85 percent of Americans, with the 15 percent at the top getting a tax cut. That's precisely what we don't need at this time, and he got called on it last night.

KING: What does it teach you about the politics of the moment, again, that this guy can go from nowhere to the top of the Republican pack? He's a bit of Ross Perot. He has some Tea Party appeal. What's in the water? Because your guy's going to be running in this political climate.

AXELROD: Well, I think there are two things to take away from this.

One is that, as I said, I think there's a tremendous amount of jaundice about politics, generally, today. And that permeates all -- on both sides. I think you can sense that. People are very unhappy with Washington, unhappy with the political system because of the perception of gridlock in Congress and some of the positions that have been taken there.

But there's another takeaway, John, which is, we have had Romney and an un-Romney in a variety of iterations throughout this campaign. Michele Bachmann filled the role for a while. Rick Perry soared to the top, and when he came down to earth, Cain took his place.

Romney sits there at 23 percent, 24 percent of the vote in all these polls. And the question is, why aren't they buying Mitt Romney? And I think it goes back to this question that we raised earlier and that he raised himself last night with that unintended revealing comment. People don't know where his core is. They don't know what he believes and what principle he's actually fighting for, other than his own advancement politically.

I think that makes people uncomfortable in the Republican primaries. I think it will make people uncomfortable should he be the nominee in a general election campaign.

KING: You're watching this all play out now. You're doing a lot of research and taking a lot of notes. If the president of the United States called you this morning and said, David, based on everything that you have learned so far, and the latest lessons you learned last night, which one of these guys or woman -- Congresswoman Bachmann is up there as well -- which one of these Republicans is best debater?

I'm not asking you to rate their policies. I'm not asking you to dig deep into the proposals. Which one of them do you think right now is the best debater?

AXELROD: Well, I think that Governor Romney's done very well. He's slipped a lot of punches. He's not been held accountable for a lot of conflicting statements that he's made over the years and conflicts with his record. And he's presented himself well.

And I think this is one of the advantages he has in this race. He's been running for president for six years. He's been around this track. And he's a more confident candidate now because he's had the experience of running once before. And it's shown up -- it's shown up in these debates.

KING: Let's talk about your side. You're obviously the chief advocate for the president of the United States. You're planning his campaign strategy.

He sat down with ABC's Jake Tapper yesterday. You like to say this will be not a referendum, but a choice. And Jake asked the president, well, grade yourself. Give yourself a grade, so the voters can get a sense of what you think of your performance.

And the president said he wouldn't do that. Then he said, at best, incomplete.

Hope and change was the motto four years ago. Can you campaign on, I need four more years to finish the class?

AXELROD: Well, I think there's no doubt that we do need four more years.

The president came in under really adverse circumstances for the country, and has been essentially an economic triage unit since he arrived there. But there are things that we need to do, not just to create more jobs in this country, but also to make sure that we create an economy, rebuild the economy in a way that work pays, that responsibility's rewarded, responsibility is held accountable and people can get ahead again.

That's going to take some time. It took a long time to get into the mess we're in. It's going to take some time to get out. So I do think that that is a factor. And he's right to give himself -- he's right to give himself an incomplete. We have got more work to do.

KING: I am fascinated by it, but I don't know what to make of it. And I'm talking about Occupy Wall Street. We have seen the large demonstrations. You're in New York City today. We have seen other demonstrations, some small, some medium, some relatively large in other cities across the country.

The question is, is this a protest movement? Will it become a big political movement? Again, in that conversation with Jake Tapper, here's the president's take.

(BEGIN VIDEO CLIP)

BARACK OBAMA, PRESIDENT OF THE UNITED STATES: I understand the frustrations that are being expressed in those protests. In some ways, they're not that different from some of the protests that we saw coming from the Tea Party.

Both on the left and the right, I think people feel separated from their government. They feel that their institutions aren't looking out for them.

(END VIDEO CLIP)

KING: Some people say this could be the Tea Party of the left. Other people say, David Axelrod, take a walk through those parks and you will see fringe left radical elements that aren't really going to be a potent punch at the ballot box. Who are they?

AXELROD: I think the important thing to recognize is that some of the sentiments that have been expressed are much more broadly held than simply in a park in Lower Manhattan.

All around this country, around watercoolers and at kitchen tables, people are expressing some of those same frustrations, hardworking people, middle class people who have done everything right, met their responsibilities, and yet have seen their wages flatlined or fall, their expenses rise, their home values fall.

And some of it, a lot of it has to do with some of the things that happened in the last decade in places like Wall Street that plunged the economy into the mess that we're in, and, frankly, Washington wasn't doing its job in sufficiently policing the market so that things were transparent and aboveboard.

So these frustrations are widely held, John. And whatever the outcome of these protests, we shouldn't underestimate that sense of frustration and the pervasiveness of it. I think it's a very central theme in our country and in our politics right now.

KING: And do you worry that the frustration could well be directed at your guy? Number one, he's an incumbent, and sometimes when you're the incumbent, whether it's fair or unfair, you catch that harpoon.

Number two, your president did raise a lot of money on Wall Street and continues to solicit money on Wall Street. And, number three, a lot of the people around him, the chief of staff, Bill Daley was of course a senior official at J.P. Morgan Chase. Gene Sperling, one of his top economic advisers, has past ties to Wall Street and Goldman Sachs. Jack Lew, the budget director, again, has some past ties to Wall Street and Citigroup.

Do you worry at all that your guy could be a symbol, could be a target of their frustration?

AXELROD: Well, all I can tell you is that, if I hear the testimonials of people on Wall Street correctly, they don't agree with that.

There's a great deal of unhappiness amongst some quarters on Wall Street about the kind of financial reforms the president fought for and is administering to try and prevent the kind of crisis that we had before and to hold all these institutions accountable for what they do.

And so if people care about these issues, and if they're looking for a president who identifies with the struggles of everyday people and the struggle of the middle class and is working for an economy in which the middle class is growing and not shrinking, then we're going to do very well with those voters, and we should.

KING: David Axelrod, appreciate your time tonight.

AXELROD: It's good to be with you, John.

KING: Thank you.