His name is John P. Coffey Jr., but since he was a child in Hempstead - the oldest of seven children of an immigrant Irish couple - he has answered to Sean.
Coffey, a 53-year-old Democrat, served as a federal prosecutor before gaining huge success as a private litigator. He retired as a U.S. Navy captain in 2004 after 30 years of active and reserve uniformed service.
Now Coffey, who lives with his wife and three kids in Westchester, looks to succeed Andrew Cuomo as the state's attorney general - and is one of several who have raised more than $1 million for that contest.
Unknown in politics, he's well-known in the legal world - perhaps best for heading the high-impact WorldCom securities class action in 2005 and the Arthur Andersen LLP audit malpractice case in 2002.
"One of the things about the WorldCom case I'm most proud of," he says in a crowded restaurant near Grand Central Terminal, "was that we made the directors for the first time in history pay personally" for the firm's fraud.
Why, after a glowing and varied career, join a scrum for statewide office now? "The corny but truthful answer: I believe in public service, particularly when times are tough and I've been blessed in my life," he says. "I look around the state, and it's a mess, and I think I can be part of the solution."
He insists that he can prove himself a unique fit for the job. He ticks off reform planks, matches parts of his resume to the AG's different duties, and proclaims the post "a capstone, not a stepping-stone."
Sean Coffey displayed discipline, smarts and hustle through his time at Chaminade High School and then the U.S. Naval Academy. He was at one point commanding officer of an elite Reserve P-3 Orion squadron. Later he became a personal assistant to Vice President George H.W. Bush - who recently e-mailed congratulations on taking the leap into the public arena.
"I see Mr. Bush Sr. as an outstanding role model of what a public servant should be," Coffey says. "That's not to say I always agreed with his politics because I certainly did not. But as a decent person who, in my view, tried to act in the best interests of the country, he was a very, very good role model."
Among other recollections from that time: The late Rev. Robert Drinan, a congressman and Georgetown University teacher, sponsored him in an arms-control seminar, where he sided against the "Star Wars" missile shield then pushed by President Ronald Reagan.
Looking back further, he recalls Hempstead as a tough place where he'd regularly get robbed by a guy named Hugo of money he collected on his Newsday delivery route. He spent seven summers with maternal relatives in County Cork as the "lucky cousin" who got to grow up in the U.S., he said.
Interesting if tangential coincidences arise from his Nassau roots. Coffey's late father, a carpenter, was a friend as a young man of Denis Dillon - long before the latter became district attorney. And now, Dillon's successor, Kathleen Rice, also is preparing to seek the nomination to succeed Cuomo - who's expected to announce soon for governor.
"One of my brothers dated one of her sisters," Coffey notes.
Records show he contributed $5,600 last year to Rice's district attorney campaign committee.
"Kathleen persuaded me she was the right person to be Nassau district attorney for the next four years," he explains.
"I still feel that way," he adds with a smile.