The one-time front-runner for the Republican presidential nomination, Jeb Bush has spent months trying to climb back to the top of crowded race with little success. In an exclusive interview with Bloomberg Politics, the former Florida governor says his campaign will last for the weeks and months to come. 

He's hoping to "exceed expectations" in Iowa, have a strong showing in New Hampshire, and have his brother, former President George W. Bush—"the most popular Republican alive"—join him on the campaign trail, probably by South Carolina. 

Bush called on everyone of the Republican field to follow his lead—and Mitt Romney's advice—and release their tax returns. He also questioned U.S. Senator Ted Cruz's foreign policy credentials; said his fellow Floridian, U.S. Senator Marco Rubio, was "hypocritical" for complaining about political attacks; and said Donald Trump's campaign was about personal ambition.

Here is an edited and condensed partial transcript of the conversation during a 30-minute ride Wednesday in his campaign's SUV:

What is the Bush campaign's goal in Iowa? Does your path back start here?

My goal is to do better than what were polling at and not have expectations beyond that. There's so many candidates. I guess my point is the difference between fourth or third, and sixth, could be two percentage points. It could be a couple thousand people.

Does it matter if you’re at 3 percent or 6 percent, or whether Marco Rubio is at 14 percent or 9 percent?  

It shouldn’t. But I’m not in charge of that. That’s the cumulative beating of the pundit tom-toms. I don’t know how you and everybody come up with it. Is there some secret squirrel meeting where you all come up with this?

I've learned really not to fret too much about the things I can't control. I’m proud of the team here and what we’re doing, and I think we will beat expectations from that regard.

And then New Hampshire, every state influences the next. But the early states aren't as influenced perhaps as once you get past South Carolina. Once you get past South Carolina, the context of the campaign is more influenced by whose moving up, who’s moving down. These first four states are fairly independent of one another in that regard.

Think about it. In my brother’s case, he won Iowa against McCain in 2000, lost New Hampshire, won South Carolina. Romney tied Iowa, won New Hampshire, got crushed in South Carolina. So the influences are not all that they appear. The states are pretty discrete and unique.

So does that mean the field won’t winnow until after March 1?

I don't think there's going to be a mass exodus out of the race. I might be wrong.

How does the establishment wing coalesce itself?

I think it coalesces itself organically by the process moving on. What people might be missing is you’ve got the first phase of this, which is February, then you’ve got a chunk of states where it won’t be conclusive because of the proportionality.

And then you get to March 15, the first time where there could be a movement forward for one candidate. Or it could continue that way for a while. You start getting into states that are different, broader—Michigan, other states—I don’t think people are looking at this from the long-haul perspective.

So you don’t think if Trump wins Iowa and New Hampshire—which no non-incumbent Republican has done before—that he doesn’t run away with this?

No. I think there’s a long-haul part of this. He hasn’t gotten the scrutiny that traditional candidates have gotten.

Talking about the establishment—what about Mitt Romney? Have you talked to him lately and whether he’ll make an endorsement in New Hampshire?

He would be a factor. He’s still held in high regard. I hold him in high regard, and I think a lot of other people do, too. I don’t know what he’s thinking. I think he sincerely wants a constructive role. He feels connected to the party. In many ways, I view him as the elder statesman of the Republican Party now.

He can play a constructive role in some fashion going forward. I just don’t know how that plays out.

Twitter: Mitt Romney on Twitter

Romney tweeted recently that all Republicans should release their tax returns.

I like that. What he was talking about was a more broad disclosure, rather than these forms the federal government provides that are kind of vague.

What does it tell us that we have not seen recent tax returns from Trump or Rubio?

Why shouldn’t they? I think they should. ... I’ve had the advantage of being around the track a few times, being from the family that I’m from. Trust me, there are a lot of investigative reporters.

I’m the most investigated, scrutinized candidate. And I’ve been totally open about my life. I think that’s the better approach to dealing with Hillary Clinton, who effectively to get information out of her you have to get a subpoena. So why wouldn’t our candidate want to be fully transparent? I think Republicans should demand it.

(Bush points out what appears to be a homemade sign supporting Bernie Sanders’s Democratic presidential campaign. The car passes, and several in the car shout out, “Feel the Bern!”)

That’s pretty cool. I love the Bern. That ad, by the way, what a phenomenal ad—the Simon & Garfunkel ad? It’s great.

So are you pulling for Bernie Sanders on the Democratic side?

No, no. (Laughs). I don’t got a dog in that fight.

You think Bernie has a chance?

Oh, yeah. The real focus is the fracturing of our party and the breaking up of parts of the conservative movement. And then you look at the left and it’s very similar. It’s very similar to how our society is fracturing, how the press is fracturing. Most institutions in our society are morphing into things that are different.

What are the differences between you and Ted Cruz?

I’m an executive with a proven record. He modulates his views in the way people expect politicians to do. His views on Syria are the best example of that.

When it wasn't popular amongst Republicans to encourage a strategy to be created to deal with ISIS and Assad, he sounded more like Rand Paul. Then the attacks occurred, and Republican primary voters and generally Americans view national security as a bigger issue and are concerned about these threats, and now he talks about "carpet bombing."

Should Cruz’s role in the government shutdown disqualify him from being president?

It doesn't disqualify him. It doesn't translate to what we need a president to do.

We need the next president to actually make government work again, have budgets that are passed. Try to find common ground and not hold our democracy hostage.

He's a gifted guy, I mean being next to him at the debate, he can bring it. He's really good at the turn of a phrase and all that. But that doesn't necessarily mean you're going to be an effective president. I think he’s a consistent conservative, at least. That separates him from Trump.

What does it say about Marco Rubio that he’s not as aggressive as you in going after Donald Trump?

It’s not even close. And it’s not just Marco, but others as well.

I can't explain the strategy. I can't imagine he can be supportive of the things that Trump says. I don't know what his deal is on that. I just know that we're running for the president of the United States. It's a job that requires leadership skills, and we’re never going to solve our problems unless have a unity of purpose right now.

Trump’s campaign right now is not a purposeful one, other than projecting himself forward. It’s not about people’s aspirations, it’s about ambition.

Is Rubio ready to be president?

I'm more ready to be president. That's for sure. The fact that you don't have practical experience doesn't mean you can't do it.  But if you've had practical experience, and its proven to be successful, it's an advantage.

You’ve called Donald Trump a jerk for mocking a disabled man, and released a TV ad about that. How do you square that with your criticism of Trump that he’s trying insult his way to the White House? 

The difference between me saying Donald trump is a jerk and him calling a huge numbers of Americans a jerk is the difference between him calling me the litany of things he calls me—I could care less. It’s not about me, it’s not about him. It’s about insulting the American people. There’s a huge difference when you make fun of all disabled people by the signal you send. People don’t like the fact that I called him a jerk. I called him a jerk because he insulted the American population.

That’s the bigger issue. There’s no parity here between what he said about me and what I said about him.

You focus a lot of your stump speech on Trump, but your super-PAC has focused a lot on Rubio.

Rubio, Kasich, Christie and Trump.

Yes. But it’s been mostly aimed at Rubio. Are you ok with that? Was that part of the strategy before this began?

We have no coordination. My focus is on me first and foremost, and then Trump as not the kind of leader we need was not focus-grouped or discussed. I didn’t talk to anybody about it. I just think it’s important. I didn’t talk to Danny Diaz. I did it because I thought it was the right thing to do. I talked to enough people that were hurt.

Are you satisfied with the decision to split your team between the campaign and the super-PAC?

In a perfect world, I’d love to be in charge of my whole campaign. But that’s not the world we’re in.

And just for the record here, Marco is scraping the bark off of me—and Christie and Cruz—and has his whole team out doing the same thing. He’s backing it up with his super-PAC doing the same stuff. It’s a little hypocritical to be complaining about it, exaggerating the amount of money Right to Rise has spent apparently.

Before it's here, it's on the Bloomberg Terminal. LEARN MORE