The former Florida Republican governor announced that Danny Diaz, a 39-year-old consultant known for his aggressive style, would serve as his campaign manager in place of Dave Kochel, an operative with deep experience in Iowa politics who had been brought aboard earlier this year and was widely expected to serve as in that capacity.

The surprise move came after several tumultuous weeks for Bush and amid recent polling that suggesting his standing has fallen both in national polls and in the key early state of Iowa.

Bush’s campaign-in-waiting said Monday that while Diaz would handle the campaign’s day-to-day operations, Kochel would “build and oversee a political operation to achieve success in the early states and beyond.”

One person briefed on the moves, revealed as Bush flew to Europe, said the final decision rested with Bush’s top adviser, Sally Bradshaw, who had watched with dismay as Florida Sen. Marco Rubio and Wisconsin Gov. Scott Walker appeared to run without the stumbles that plagued the two-term Republican governor.

“Sally and company felt like they were losing the media battle to Walker and Rubio. Last week this decision was made,” the source said. “Kochel found out last week.”

Another source familiar with the situation said Bradshaw, Bush’s longtime top political adviser, struggled to control Kochel, who worked on Mitt Romney’s 2012 presidential campaign.

The troubles for Bush began in earnest last month, when he suffered a spate of negative headlines for bobbling questions about whether his brother was right to invade Iraq. He has fallen well behind Scott Walker in Iowa, where a recent poll found Bush lagging in seventh place and where his commitment to competing in the state has been questioned.

Bush’s team had a series of meetings last week in Miami — a high-level confab confirmed by multiple sources. One source said that GOP consultant Rob Collins gave a presentation to a packed room of Bush higher-ups (Bradshaw was on via conference call from the Tallahassee area) where the consultants and strategists talked about each potential Bush rival, how they would attack them and how they would neutralize each dart.

One consultant who flew in, Ryan Erwin of Las Vegas-based RedRock Strategies, was reached by phone by POLITICO on Monday and declined to comment on what was discussed. “That’s a question for Miami,” he said.

Diaz, Kochel and Bradshaw refused to comment on the personnel moves. A Bush spokesman, Tim Miller, would say only that “everybody” had “been involved in the discussions” and that “the leadership of the team each feel they are being placed into their highest and best use to advance Jeb’s message and win the nomination and the general election.”

While Kochel’s new portfolio suggests Bush views an Iowa win as increasingly out of reach, it frees Kochel to devote all of his time to three tasks: helping Bush finish near the top in his home state of Iowa, winning in New Hampshire and running competitively in South Carolina.

“Dave Kochel is one of the best political operatives in America. Played a key role in Mitt Romney winning [the nomination] and in many other tough wins,” wrote Romney’s former top adviser, Stuart Stevens, in an email. “Any campaign is lucky to have him on their side.”

The complications came within the framework of a campaign that has emerged as a fundraising juggernaut but with a yet-to-announce candidate. Though there was a consensus style of leadership — with Bradshaw as the first among equals with Kochel and consultant Mike Murphy — there was no clear manager to keep the trains running on time.

While Kochel was widely expected to be the campaign-manager-in-waiting, sources say that Kochel’s hiring by Bush’s team should be put in context: Bush locked down Kochel’s services when Mitt Romney was himself contemplating a run and thus denied a potential 2016 rival the talent of a former top operative.

Opposing campaigns viewed the decision to tap Diaz as campaign manager as a signal that Bush — who once said that he wanted to run for president “joyfully” — is preparing to run a more bare-knuckled campaign.

Diaz, who has never before served as a campaign manager, is known for his experience in the world of opposition research. Until being named to the new post, Diaz — who’s worked for clients ranging from Illinois Sen. Mark Kirk to the National Republican Senatorial Committee to former Virginia Attorney General Ken Cuccinelli — had been advising Bush’s exploratory committee on communications matters.

In recent days, Bush has acknowledged that he’s preparing for a tough campaign. “Look, it’s a rambunctious deal,” he said at a Republican cattle call in Florida last week, in response to a question from an audience member about whether he expected the race to become more negative. “It’ll be competitive. There’s gonna be some elbows and knees under the boards. This isn’t tiddlywinks we’re playing.”

Those who’ve worked with Diaz describe him as tenacious — and sometimes overbearing. In political circles, his fiery temper — often used against co-workers and reporters covering the campaigns he’s working on — is widely known.

Bush drew praise in some quarters for the staff shake-up, with some observers saying it showed his eyes are wide open to the challenging campaign ahead and that it was smart to recognize the need to bring aboard a dynamic figure.

“I’ve worked with Danny, and he’s a [expletive] animal,” said an adviser to a rival Republican candidate. “If Danny is capable of transmitting a third of the energy he possesses, it will be a marked improvement over where Jeb had been.”

While making the move so close to his expected June 15 official campaign launch isn’t ideal, some said Bush acted wisely by moving sooner rather than later.

“You make changes as quickly as possible. You don’t wait for things to play out,” said Dave Carney, who helped to guide Rick Perry’s 2012 presidential campaign. “It’s smart to do these things now.”

The Diaz hire was one of several personnel moves Bush announced on Monday. The former governor also formally tapped Murphy, his longtime political adviser, to head his super PAC. Jon Downs, a Republican consultant who is business partners with Diaz, will oversee the media advertising effort for Bush’s official campaign.

In a statement announcing the moves, Bradshaw said: “David can best position us for success by playing a key leadership role focusing on how Jeb wins primaries, caucuses, and ultimately the general election and Danny’s skill at rapidly moving content and campaign organization makes him perfectly suited for running the day-to-day operations.”

Bush, flying to Europe on a weeklong trip to meet with foreign leaders, is traveling to Estonia, Germany and Poland. He will return Saturday to prepare for his expected campaign launch Monday.

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