Just look at the precedent it sets. Even if you're a hardcore supporter of the president who says, "We want to build a wall," think about this. What if the next president who comes in ... let's say it's a far left, a Democratic president, who says, "I think climate change is an emergency. I'm going to skip Congress, and I'm going to declare a state of emergency to enact the Green New Deal." Who's to stop him?

Larry Hogan: I thought the entire thing was mishandled from the beginning, but the most recent iteration of this declaration of emergency is a mistake. It's not what the constitution had in mind.

John Harwood: Well, let's talk about the president for a minute. You saw the other day the president having seen a bipartisan agreement in Congress, signing it, but then going and declaring a national emergency under circumstances that you yourself have said is not an emergency. What does that tell you?

Larry Hogan: Well, I'm concerned about the Republican Party, I'm concerned about the country, I'm concerned about both parties quite frankly and the broken politics of today. It's the thing I'm most frustrated about, and I think many Americans are concerned about. It's this anger and divisiveness on both sides, where people don't really seem to care as much about fixing problems. They're more concerned about pointing fingers and winning arguments, and not really coming up with solutions.

John Harwood: What do you see happening in Washington to your party and to your country?

Larry Hogan: I'm doing great. Thank you for asking. I've been cancer free now for a couple of years, and feeling healthier than ever. I didn't quite get all my hair back ever, but other than that I'm feeling great.

John Harwood: I can't start the interview without taking note of the fight that you had with cancer beginning in your first year in office. How are you doing right now?

Hogan sat down with CNBC editor-at-large John Harwood at McGarvey's, an Annapolis bar near the governor's office, to discuss his concerns about Trump and the possibility he'll launch a campaign against the incumbent. What follows is a condensed, edited transcript of their conversation.

The stout, personable Republican — who this summer will become chairman of the National Governor's Association — wields immense popularity even in a strongly Democratic state. And he carries a resonant family legacy of political fortitude. In 1974, his father, Rep. Lawrence Hogan Sr., became the only GOP member of the House Judiciary Committee to vote for all three articles of impeachment against Republican President Richard Nixon.

Four years later, re-elected and cancer-free, Hogan has attracted 2020 attention. Dissident members of the GOP searching for someone to challenge President Donald Trump's renomination have turned to him for two reasons.

Until recently, no one thought of Larry Hogan as a candidate for president. His first two campaigns for office ended in defeat. In 2014, he won the Maryland governorship at age 58 — and within months received a diagnosis of Stage 3 non-Hodgkin's lymphoma.

John Harwood: Your dad as you noted was an FBI agent. When you hear the president attacking the FBI as a corrupt institution, does that strike you as someone who has been unfairly targeted by a corrupt institution, or someone who is very concerned about what a legitimate investigation is going to find?

Larry Hogan: Well look, I can't read the president's mind or try to opine. I don't know what the president was thinking or why he says or does certain things. And I don't know all the facts of the case. But I do believe that the FBI is a proud organization.

John Harwood: Do you have confidence in the current FBI investigation based on everything that you know?

Larry Hogan: I'm very hopeful that the FBI investigation is going to be fair and maybe take a look at the facts. But no man is above the law, not even the president of the United States. They need to get to the facts and the truth. I don't want an unfair investigation that's just trying to undermine the president. But I don't want the president stopping an investigation either. I just think we want to get to the truth. I don't know the truth, but I think the people deserve to get the truth.

John Harwood: But you have no reason to believe or to think that that is an unfair corrupt investigation?

Larry Hogan: I certainly don't have any reason to think it.

John Harwood: Let's step back a little bit. Do you see a straight line between the Nixon Republican Party and the Trump Republican Party?

Larry Hogan: I don't think so. I think people are trying to draw the parallel because of the talk of impeachment, but I don't know that there's many similarities. Nixon was really focused on opening up trade and working with foreign nations and opening up discussion with China, and it's sort of the opposite of some of the things that are going on now.

My concern about the party now is that we're focused on a smaller and smaller shrinking base. I happened to just win re-election in one of the blue states by winning a third of the black vote, winning the women vote, splitting the Latino vote and getting a huge number of Democrats and independents to cross over and vote for me. I'm not sure the Republican Party can continue winning national elections if we can't win the women vote, we can't appeal to any minorities, and if we're constantly shrinking.

I think the party needs to find a better way to reach more people and to find consensus without abandoning principles ... that the party has stood for, on economic growth, on job creation, on tax cuts, without just getting to a smaller and smaller base where, if you don't agree with us on 100 percent of these issues, you're an outcast, an enemy, and we don't want you, which seems to be some of what's going on today.

John Harwood: Mike Pence [recently] went to the Munich Security Conference, praised Trump, and was met with silence from our allies. What does it tell you about where the Trump administration has taken the United States in terms of our place in the world?

Larry Hogan: Well, it's definitely concerning. I do think there's concern among a lot of leaders around the world that America is not in the same position of leading that it once was. Some of the positions we're taking on trade and on our relations with other countries are not helpful, and so I think that's a healthy debate that we need to have.

John Harwood: That Munich conference was paying tribute to John McCain. You had John McCain's speechwriter, Mark Salter, work on your second inaugural. You had Jeb Bush, of course, whose father served with your father at your second inaugural. What message were you trying to send to the Republican Party?

Larry Hogan: I wasn't really trying to send necessarily a message to the party or to President Trump. These are just guys that I admire. I grew up knowing and respecting President Bush, H.W. Bush, and he served in Congress with my dad. I went to his funeral, which is where I saw Jeb, and I thought he did a great job as governor of Florida. He's somebody I respect, and I asked him to come to speak at my inauguration. McCain, I've always admired because he always put his country ahead of himself or his party throughout his career.

John Harwood: Does President Trump do that?

Larry Hogan: Well, I'm not sure he always does. One of the things I probably was most angry with or most frustrated with Donald Trump about before he was president were the comments about John McCain not being a war hero when the guy sacrificed his life and spent all that time in a prisoner of war camp and stayed there when he could have gotten out.

John Harwood: As you know, a lot of people took the presence of Jeb, the involvement of Salter, your invocation of your dad at the inaugural as a sign that you're considering running for president in the Republican primary against President Trump.

Larry Hogan: I wouldn't say considering it. I've been listening to a lot of people who've been trying to encourage me. I have not been really giving it a whole lot of personal thought.

John Harwood: You haven't told those people, "No."

Larry Hogan: I didn't say, "No." I didn't say, "Under no circumstances would I never do it." There is a difference. I just got sworn in a month ago. There are more things I want to get done, and I also don't want to go on some fool's errand. Nobody's successfully challenged a sitting president in their primary since 1884, and I don't want to just run around the country and put my family and everybody through that kind of an effort for no reason.

Now, if things change in the future, if the president weakened, and I really thought it was important to the country or the party, maybe later I'd be willing to consider it.

John Harwood: But you are concerned about this president, who you did not endorse, and who you might run against.

Larry Hogan: Well, I don't know about the I might run against part. I am concerned. There's been no secret. When I disagree with the policy or when I think something is happening that is wrong, I'm not afraid to stand up and say so, and that probably puts me in a different category than many Republicans, who I think, sometimes, feel the way I do, but they won't say anything about it.

John Harwood: Well, to that point, I talked to a couple Republican members of Congress over the weekend, and one of them I was talking to about things the president had said about the border wall which weren't true. I was asking, "Do you agree with that?" And his answer was, "Well, you can say that, but I can't say that."

Larry Hogan: Hey, you say it. I can't say it. Look, I'm a leader in the Governor's Association. I talk to Republican and Democratic governors on a regular basis, and I can tell you, without naming names, that there are a number of my colleagues that have shared with me, privately, that they're very concerned about a lot of things, but they won't speak up or ... they may be concerned about, in a red, red state, they're going to be primaried or challenged or attacked by the president on Twitter, or the base is going to get angry, and they'll quietly say, "I agreed with what you said," or, "I agreed with what you did. I just can't say it."

But I'm not running for re-election. I'm term limited. I'm in a very blue state that the president lost by 29 points.

John Harwood: Now, there's some people making the argument, Bill Kristol among them, I know he's talked to you, and some others, that it's important, even if a primary challenger can't win, it's important, as a matter of principle, that the Republican Party have someone run reflecting the kind of Republican Party they think ought to exist.

Larry Hogan: I've heard that argument from dozens and dozens of people, including Bill Kristol, and many people feel pretty strongly about that. I wouldn't argue with that point. Whether that's something I could do or would do, I have to take into consideration my state and does it make sense to go running around the country to make a point or to do something for the greater good that then takes me away from my day job.

John Harwood: But if the reason was to make a point about the Republican Party, even if you didn't win, you would not be willing to do that?

Larry Hogan: It's funny. Somebody made the case the other day, and I won't tell you who, but they said, "What would your dad do?" Now, that's a low blow. You can't be pulling that one on me. What would be the right thing to do for the country and the party? And that's something that would require a lot more thought, whether that makes sense or not. I'm not ruling anything out.

John Harwood: Do you think if you had your 26 fellow Republican governors in this room, that most of them would say, "Go, Larry, go"?

Larry Hogan: No. I don't think that's the case. I think a lot of them are very strong supporters of the president and they're in very red states, and they, certainly, on your camera, none of them would say that. If we were having a beer and no one was listening, probably half of them might say, "It's worth a shot."