If Donald Trump has so far succeeded with his disregard for the conventional rules of presidential politics, his hiring this week of seasoned Republican hand Paul Manafort seemed to signal an acknowledgement that the rules are now paramount.

Manafort is a “master” of delegate counting and convention strategy, according to those who have worked with and against him, and one of only a few operatives with practical experience in this niche area. For a campaign whose survival might well hinge on a few dozen delegates, Manafort’s hire is a monumental, if surprising, coup.

“The fact that Trump hired him is a serious move forward,” said Scott Reed, now the senior political strategist for the U.S. Chamber of Commerce, who managed Bob Dole’s 1996 campaign for president -- on which Manafort also worked. “Paul is a proven vote counter, he knows how to strategically move a campaign."

Reed added, “It hasn’t gone unnoticed by [Ted] Cruz and [John] Kasich.”

Indeed, Trump’s rivals have been working furiously behind the scenes to assemble their own teams of delegate hunters. Cruz’s success in this area recently riled Trump, when allies of the Texas senator grabbed five of six slots on key panels selected at the Louisiana GOP’s state convention. Trump threatened a lawsuit before campaign aides walked those remarks back, saying they would contest the result through state party channels.

Kasich’s campaign, meanwhile, announced earlier this month that it would bring on Charlie Black, a veteran of Ronald Reagan’s 1976 campaign and convention fight. That convention, the sole modern precedent to what might transpire this year, is where Manafort cut his teeth, too, hunting delegates in the lead-up and then managing the floor for President Gerald Ford on a team steered by James Baker. Ford ultimately prevailed over Reagan by just 117 delegates.

On Reagan’s side in that contentious primary was Roger Stone, the now-informal Trump adviser who recommended Manafort to this year’s front-runner. Manafort and Stone’s relationship has its origins in the Young Republicans, where the two men together clashed during formative years with two other future GOP operatives, Karl Rove and Lee Atwater.

“Atwater and Rove were in one faction, and Manafort and I were in another faction, the more conservative faction,” Stone recalled. “These fights don’t amount to much, but they do give you enormous experience.”

For Trump, who has cast himself as an outsider to the Republican Party firmament, there could hardly be a less outsider-y pick than his new hire. Manafort was uniquely predisposed to become an insider in Republican politics: His father, for whom he was named, served as mayor for three terms in New Britain, Conn. When the elder Paul Manafort died in 2013, his obituary noted that he had served as a delegate or alternate delegate at past Republican national conventions.

"I was brought up in a political family," the younger Manafort told the Cincinnati Enquirer during the 1972 Republican National Convention in Miami, when he was a law school student with a national role in Young Republicans. "It was drilled into me that I should put time into politics and community activity. I began to feel that it was an obligation to get active within the political framework."

After law school and a brief stopover at a company where his father also worked, Manafort fulfilled his obligation and joined Ford’s presidential campaign. There, he ended up working out of a Washington, D.C., office as a delegate-hunt coordinator on a small team under Baker.

The process of delegate hunting is not unlike a nationwide whip operation, demanding deep knowledge of each delegate, how he will vote in the second round of balloting (or the first round, if the delegate is unbound) and what factors could sway him. Baker’s team homed in on pockets of uncommitted delegates.

On the team with him was Peter Roussel, who today teaches in the department of mass communication at Sam Houston State University. Roussel took to calling Manafort “roomie” because they were both assigned to a glorified closet space, where they pulled late-nighters and talked baseball.

“He was a very smart guy, very organized,” Roussel recalled. “When he spoke, you paid attention.”

Manafort’s work on the ’76 campaign attracted the attention of Reagan’s camp, which hired him as southern coordinator for the Gipper’s 1980 campaign, where Manafort reunited with Stone. Later, in 1980, Black, Manafort and Stone together founded a lobbying firm that bore their names, while operating a political consulting outfit along with Atwater. Their work ushered in the era of the never-ending campaign, when policy and politics became inextricably linked.

The lobbying firm, however, developed a reputation for controversy. In 1989, Manafort was called to testify before Congress over tens of millions of dollars in federal money he had helped secure for a New Jersey low-income housing development -- money that apparently had been squandered.

“We played by the rules,” Manafort insisted to the congressional panel.

When one member of Congress charged him with “influence-peddling,” Manafort objected. “You might call it influence-peddling,” Manafort said. “I call it lobbying.”

Even as Manafort earned a reputation in his political career as a shrewd vote counter and convention expert, he developed another as a mercenary who does not shy from controversial clients — a quality that might explain what drew him to Trump.

“Paul is attracted to heat,” said one Republican strategist who has intersected with Manafort professionally, “not repelled by it.”

Manafort began advising Ukraine’s Viktor Yanukovych in 2005 and steered his successful campaign for president there in 2010. But Yanukovych was overthrown by a popular uprising in 2014 that captured international attention, with his administration widely accused of corruption.

That work in Ukraine is one piece of a larger international portfolio Manafort has built in recent years, which led many of his connections in Washington to believe he had quit the U.S. politics game. But as Manafort now returns to take a most unusual assignment, he returns also to his comfort zone. His campaign role will be a familiar one; meanwhile, Manafort has known Trump for many years and will command his respect, those who know him say.

“He’s well-to-do and doesn’t have to take any crap from Trump or anyone else,” said Ed Rollins, who first met Manafort on Reagan’s 1980 campaign and worked with him in Republican politics for many years after that. “He’ll do it his way, or he’s not going to do it.”

(The Trump campaign did not respond to an RCP request for comment, nor one to connect with Manafort.)

Stylistically, Manafort might be a natural fit for Trump: Like the boss, he is said to be aggressive, even ruthless. And, in a historically exciting primary election with the delegate count and convention at the center, there will be plenty of heat. Just as Manafort likes it.

Said Stone, “The sharpies in the party who thought they would just razzle-dazzle the neophyte Trump people now have their hands full.”