WASHINGTON — Growing up in Hingham, with a self-described “idyllic childhood” where his Dalmatian followed him on the walk to school, Phil Cox was far more concerned with his hockey game than with politics.

His senior year at Hingham High School, he was the left wing on the state championship hockey team.

“I got the Mr. Hustle Award,” he said. “Which is for the guy who isn’t the most talented, but works hard.”

Many say he is still deserving of the Mr. Hustle Award.

Cox, who grew up in one of the most liberal states in the country, is wrapping up his tenure as executive director of the Republican Governors Association. He oversaw a hugely successful election cycle where Republicans held onto competitive seats in Wisconsin, Florida, and Maine, while winning new seats in states like Massachusetts, Maryland, and Illinois.

Cox, 40, is credited with much of the success, and is now expected to be perhaps the most sought-after adviser in a crowded Republican field of 2016 presidential candidates.

“I think he’s the preeminent strategist in our party right now,” said Ed Gillespie, a longtime top Republican consultant who just narrowly lost his US Senate campaign in Virginia. “Anybody who doesn’t go after him to be their presidential campaign manager is crazy. . . . If I were advising a Republican presidential candidate right now, the first thing I would say is, ‘Call Phil Cox and see if you can get him on board.’ ”

Cox also made a deep connection — over both sports and politics — with New Jersey Governor Chris Christie, who was chairman of the RGA and is considering a presidential run.

“I like him,” Christie said in an interview. “Plenty of people in this business you work with that you’re not particularly fond of on a personal level, but I was really fond of Phil.”

Cox, the youngest of three, grew up in the Liberty Pole neighborhood of Hingham, going to public schools and playing baseball, golf, and hockey.

Growing up, his mother, Phyllis — a social worker who worked for hospice care — leaned Democratic. His father, Jim — a longtime pediatrician at South Shore Medical Center — was a Republican. He remembers, as a 10-year-old, watching the 1984 conventions gavel to gavel on television. He was interested in politics, and history, but wasn’t particularly active otherwise.

“I don’t think anybody would have looked at me at 18,” Cox said, “and guessed that I was going to be running the RGA.”

Just after graduating from the University of Virginia, he managed a local race for Paul Harris, who in 1997 became the first black Republican elected to the Virginia House of Delegates since Reconstruction.

“It was very appealing to me at the time,” Cox said. “I always loved athletics. One of the things that appealed to me was the pure competition of it, and the fact that there was a winner and a loser.”

In 1999, he started a consulting business and had 23 clients. He won 22 out of 23 races.

He was hooked.

By 2006, he was second in command at Americans for Prosperity, the conservative political advocacy group funded by the Koch brothers. He ran Bob McDonnell’s gubernatorial campaign and then joined the RGA, first under Mississippi Governor Haley Barbour and then under Texas Governor Rick Perry, McDonnell, Louisiana Governor Bobby Jindal, and Christie.

It’s a role that many governors have used to elevate their national platform, making more connections, raising money, and paving the way for higher office. Cox and Christie saw eye to eye on many of the organization’s strategic decisions, recruiting candidates to run and spending heavily on those they backed.

They made a decision to invest early in New Mexico, South Carolina, and Iowa — all states with Republican governors that at one point could have become competitive.

Cox had a particularly strong role in recruiting Charlie Baker to run in Massachusetts. Baker had initially called Cox in 2009, asking him if he would run his first gubernatorial race. Cox, who was in the homestretch of a campaign he was running in Virginia for McDonnell, declined.

But a few years later, Cox was the one recruiting Baker. Cox said he had a brief phone call with former US senator Scott Brown — “it was very clear to me that he wasn’t serious about it” — but he thought Baker was their best shot.

“I was very focused on trying to get Charlie to consider running,” Cox said. “I developed a real friendship with him over the years, and I thought he had taken the lessons of 2010 to heart.”

“One of the things we talked about was, particularly for a Republican candidate in a blue state, you have to show voters what’s in your heart before they’ll be willing to listen to what’s in your head. Charlie didn’t do that four years ago. He was uncomfortable doing that, showing what was in his heart. He did that this time. He did that in the debate.”

By September, Christie said, he wanted to invest in Maryland and Colorado by taking the RGA into debt. Cox was more cautious, but he came around.

“He’s very calm. This is not a guy who allows the stress of particular situations to get to him,” Christie said. “He has a very calm demeanor and in very difficult situations he is one of the voices of reason. He’s intense, but it never shows.”

Cox (a diehard Red Sox fan who can still name every player from the 1986 team) and Christie (a diehard Mets fan who relished rubbing in the 1986 World Series outcome) bonded over baseball.

One day a few weeks ago, Christie went to his office and had a FedEx package from Cox. Inside was an photo of the 1986 Mets celebrating on the field. It was autographed by all of the players.

“You’ve been really great to work with,” Cox wrote. “And you can’t imagine how much this hurts.”

“He can do whatever he wants,” Christie said. “There are going to be a lot of people coming to him — presidential candidates and other big committees who would want him to run the show. He’s going to have his choice about what he wants to do.”

Christie didn’t let on whether Cox would be on his own short list. And Cox says he’s still trying to decompress from the last campaign.

“For a guy like me, running a presidential race is the equivalent of climbing Mount Everest,” Cox said.

“I’ve always been one to look toward the next challenge. But I feel like I don’t need to do it to feel like I’m accomplished professionally. The more important job for me right now is husband and father. So I need to weigh those things.”

He might not have too long to weigh them. Presidential candidates, including Christie, are starting to gear up.