Transcript for Terry Moran: Trump 'girding for battle with a new chief of staff and a new attitude'

news contributor, Alex Castellanos. ABC news senior national correspondent Terry Moran. Shawna Thomas. Washington bureau chief for vice news. And Julie pace, Washington bureau chief for the associated press. And Terry so much news crammed into this week. It seemed so long ago that you and I were on this set talking about the passing of president George H.W. Bush. But Friday, everything returned back to Normal in that way. The Mueller investigation is front and center. And "The New York post" called it a terrible, horrible, no good, very bad day for the president. Some of the sub headlines about Michael Cohen. Trump's spat with former secretary of state Rex tillerson. The stock market slide. Fair to call it a very bad day for president trump on Friday? A bad day. Dark night. What he's doing is clearly girding for battle. With a new chief of staff and a new attitude. This is really going to be a fight to the finish. Not just for the survival of the presidency but for the people who voted for president trump. Thought he was the right direction for the nation. And the country itself. And the Democrats are on the other side. The stakes in the legal fight as it enters the political sphere. As he already is planning his re-election battle, are going to be as high as they can be. If you think the last couple of years have been terribly divisive and bad for the united States of America, stay tuned. It's distracting. I mean, how does he do his job? I was backstage thinking, oh, wait, he was in Argentina at the g20 a week ago, right? It's warp speed. All the time. Interesting news about China and trade. Interesting news about nafta at that point. None of that matters. I don't know how you do any work if you're the president of the United States in the situation that he's in. Let's go to one of the things you mentioned. And the market slide. Is that about trump's week? What is that about? I mean, I'm not an economist I will say that. I think a lot of it is uncertainty. We have seen this over and over again. We have also seen that until we know exactly what is going on with China, you had soybean prices drop for farmers out in America. I think people just don't know what -- Tariff ban? Not tariff ban? Yeah. Do we have a deal with China? Do we not have a deal with China? It's market uncertainty. Until they figure out a way to know what the president is going to do, which is almost impossible to ever know, volatility. If market uncertainty becomes economic uncertainty that becomes a problem for the president. So much of what we have seen over his presidency is that despite the chaos. Despite all of the controversies, he's been held up by a strmy. And the thing that makes his advisers, and the president himself the most nervous, is that that starts to crumble. Because that essentially is his argument. You might not like the tweets, you might not like anything unless, but look at the economy. When you talk to voters, they talk about that. We'll forgive all that other stuff as long as the economy stays strong. Alex, I want to talk to you about Rex tillerson. I want you to take a listen. Oh, okay. Okay. We don't have that sound. But one of the things Rex tillerson said was it was challenging for him coming from a disciplined, highly process-oriented ExxonMobil corporation and to go to work for a man who is pretty undisciplined. He also said he had to explain to the president what was illegal and not illegal. President trump coming back with Mike Pompeo is doing a great job. I'm proud of him. His predecessor Rex tillerson didn't have the mental capacity needed. He was dumb as a rock. And I couldn't get rid of him fast enough. He was lazy as hell. Now is a whole new ball game. Great spirit at state. Dumb as a rock? That's one of the nicest things the president has said about someone exiting. I think as Shawna said, it's the uncertainty. Donald Trump came as an outsider. He was sent here to be a disruptive force. An establishment figure like tillerson who wants to play things by the rules is not going to get along well with the president. That is the president's great strength. He's the madman negotiating theory. Right? Your adversaries and competitors don't know how to deal with this man. Tillerson got under his skin. He's the man he nominated for secretary of state. He's his secretary of state. He was the secretary of state. Yesterday's not today's. The real serious issue is that that same under certainty -- he doesn't play by the rules. That made tillerson the wrong fit. That is what is endangering the economy right now. That is this recovery is long in the tooth. We have seen signs that the whole bubble may be getting ready to pop. If it does, the president's strength, which is unchangeable, that uncertainty and disruption that he brings to everything, may become his greatest weakness with swing voters. I do think the tillerson comments, things happen in this administration at warm speed. That is an extraordinary statement to say the president didn't read, didn't know what was going on, he didn't know what was legal. I'm also remembering that it was reported that Rex tillerson called the president a moron. As someone by his side seeing the day-to-day dealings, that's an extraordinary assessment. Let's turn to John Kelly. Finally, after months and months and months of reporting, John Kelly is leaving. The reporting is now right. The reporting is now correct. Not fake news there. There's a part of me that thinks maybe John Kelly wasn't the right fit at this point. Yeah. We're about to switch into political hard core mode. Like Terry was saying. And so, because of that, perhaps a more political operator like a Nick ayers is maybe a better fit. Even with the issues Nick might have. I think the interesting thing about tillerson and the changes we're seeing in the administration right now is that tillerson was not necessarily trump's idea of who you want on TV representing him. Like, this is also the media world of trump. Whereas Nick ayers looks the part of chief of staff, even though he's young for this job. Heather nauert, probably going to be nominated as secretary of state -- I'm sorry, not secretary of state, U.N. Ambassador. Totally different. Also looks the part. And in some ways -- What is the part for a U.N. Ambassador? How do you look the part? I think she can go on TV and she can represent the president in a way that he wants to be represented. In the way he is used to. She used to be on fox, actually. In some ways, whoever can make the TV show of the trump administration the way he sees it in his head, those are the people he's choosing right now. There are a couple of things. It's true that presidents, excuse me, can operate in all kinds of different ways. Some are punctual. Some an hour and half late. There are presidents who are kindly. And some who are bullies. As long as they can get the machine to work for them, that's what matters. And president trump had a particular problem. He came into office not as a Republican, but a nationalist. As an economic nationalist and a cultural nationalist. Staffing up an administration with a party that never existed before he ran. He's looking for people to advocate for him. Who will be his guy. Including, he named a new chairman of the joint chiefs of staff nine months before he needed to do that. What does that tell you? And also a new attorney general, William Barr. What do you make of it? Prepare for turnover in a political year. I think the Barr choice is a good one. He has picked some establishment choices here, which is rare for trump. Most of his choices are disruptive. Gee, they don't have the experience. Trump is running against the very experience that his voters think has ruined the country. So, these outsider choices. I mean, "The Washington post" said hen nauert was first appointed at state, she had no qualification other than looking like Heather Locklear. Would anybody have said that about a democratic appointee. She's been in the state department for almost two years. She also worked for Rex tillerson. So she does have some experience. The key thing about Donald Trump is he was elected to disrupt and change the country. We're seeing it in his appointments. Rare is the one like bill Barr that has establishment support. And just on the military again. Why nine months early on a military appointment? I have no idea. Julie? It's a great question. It's a bit of a mystery about why -- we don't know what this means about Dunford. If he'll leave early. Or if this transition is going to take nine months. Go back to the Mueller probe quickly. And the southern district of new York. Which we have been talking about all morning. How much does this damage Donald Trump going forward? I think politically, I'm not sure, frankly. Because we have seen, up until this point, Republicans largely stand with him, as we get revelations in the sdny probe relating to payments to women and in the Mueller probe. I thought it was interesting in your interview with senator Rubio where he noted that a pardon for Paul manafort would essentially cross a line there. We'll have to watch and see if there is movement. If they do start to get nervous about the revelations from Mueller. Certainly the revelations from sdny. Which I think are incredibly significant and certainly what trump might do with relation to a pardon. Martha, how much will this damage Donald Trump? None. You can't fall off the floor. Back to the economy. All trump has is his base right now. They're sticking with him no matter what. And a Republican would look at -- And they'll say he's totally fine? No, I think they would say, Mueller has an empty holster. Usually you get the little guy to flip on the big guy for the same thing. You get the little guy to take the hit. Hey, you tell us about the bigger guy and we'll let you go. Well, there's no little guy charged with collusion yet. So Republican would say, Mueller has an empty holster on the big issue he was set to get trump on. One second. Terry, return to where we started. Which was the memorial. For George H.W. Bush. Such a powerful tribute. There was that one moment I think you all probably watched when president trump came in, went down that row. Hillary Clinton barely looking at Melania trump. Looking -- greeting her. But not ever looking at Donald Trump. It was hard to ignore the tensions there. What would your observation be? My representation was the tableau of American history that was represented there. Each one of those men were put there in that row by the American people operating through the constitution. That's our history. He doesn't like them? Tough. They don't like him? Tough. We make a big deal out of the bad blood between this president and that president. I think one of the facts the Democrats have had trouble coming to terms with is maybe one of the most undercovered stories in America. That Donald Trump is the 45th president of the United States of America. Just a last word, Shawna. Ten seconds. I read an article. It says that tableau is a message about we have peaceful turnover of power in this country. And we can talk about whether president trump, his role in this. There is something nice. H.W. Allowed us to see that. All of the presidents can sit in a church together and worship. They did indeed. Thank you so much for joining us.

This transcript has been automatically generated and may not be 100% accurate.