Michael D. Sullivan, partner of the law firm of Brown, Drew, Massey and Sullivan bounded out of his eighth-floor office with his hand out and a big smile. He should have been a red-eyed wreck and not the genial, balding man with a large grin.

When we had spoken four hours earlier on the phone he was driving back to Casper, Wyoming, after a marathon meeting in Rock Springs which had gone on until 4 a.m.. Pumped up with the adrenalin of a successful mediation, he got into his car and drove 200 miles over the Continental Divide of the Rockies through the night back to Casper for a few hours' sleep before coming to the office.

After our interview he had another meeting with three clients, during which he had his lunch of a bowl of soup. As ambassador in Dublin he would certainly eat better and get more sleep. But on that subject he has taken a vow of silence until President Clinton reveals his choice.

He seems genuinely happy being a high-powered lawyer in his beloved Wyoming. He feels honoured to be considered for the ambassadorship, but laughs and says, "I don't have to have it to exist. I'm happy with having a successful mediation in Rock Springs even if I wish it had not taken so long to get it." His polished cowboy boots show under the well-creased trousers.

His one-time political opponent, the former Republican senator for Wyoming, Al Simpson, would love Sullivan to land Dublin. He says that President Clinton owes him one for the way Sullivan came out to support him at the start of his first presidential campaign when he was seen to have little chance to get the Democratic nomination early in 1992.

Simpson lobbied for Sullivan when the President was deciding last year whom to appoint as his new ambassador to the Vatican. "You know Mike Sullivan went over the cliff for you," Simpson reminded the President, who said he had "the highest regard" for Sullivan and that Hillary and Jane Sullivan were "very good friends", but he had a "first obligation" to Lindy Boggs for the Vatican, a former Democratic congresswoman, now in her 80s.

Sullivan's former press secretary, Dennis Curran, says he once told him there were only two ambassadorships he would be interested in - Ireland and the Vatican.

So Ireland may be coming up and giving him the chance to move to the land of his ancestors, a country he has so far only visited "in my dreams". But Sullivan insists he has not asked the President for it while saying that they have become "good friends".

"He knows he doesn't owe me anything. I did what I did because I believed in what I was doing," Sullivan says. "I've never asked for anything in return and I never expected anything in return."

After Sullivan had completed two terms as governor of Wyoming in 1994, the President encouraged him to stand for the US Senate seat then becoming vacant, although a Democrat had not won a seat there for 30 years. Sullivan threw his hat in the ring but found that his friendship with Clinton was hurting rather than helping him.

In 1994, the President, after raising taxes, was deeply unpopular and not just with Republicans. So Sullivan knew that his opponents would exploit his closeness to Clinton. They ran TV advertisements showing in slow motion the President embracing him at Denver airport at the time of the Pope's visit the same year and claiming that he would just be a yes-man for the White House if elected.

At the start of his campaign for the Senate, Sullivan insisted that his ties to Clinton would not prevent him taking an independent stance on issues affecting Wyoming if necessary, but neither would he pretend they were not personally close.

"The people of Wyoming know of that relationship with the President. I don't intend to hide it. They would think less of me if they thought . . . I would run away or slink away from somebody who I have acknowledged as a friend," Sullivan told a press conference. But he did not encourage Clinton to campaign for him in the Wyoming race.

Al Simpson, whose Senate seat was not in contention that year, joined in the Republican campaign of claiming that Sullivan's friendship with Clinton could compromise him if elected. At the time the President was pushing his policies on the environment and gun controls, which were unpopular in Wyoming.

Now, four years later, Simpson admits that this was "a phoney argument but effective". Sullivan lost that Senate race heavily to his Republican opponent after a "bruising" contest. He says now that he has "no regrets" he ran, but the crushing defeat must have shaken him four years after he was re-elected governor with a record vote.

He says that what the voters were telling him this time was, "we love you but we don't want you in Washington, where we're not sure we trust those guys".

Sullivan decided to quit politics altogether and he and his wife, Jane, "took off and drove around the country" to get the defeat out of their system. They covered 10,000 miles and 29 states in 70 days "with no plans or reservations".

Even their political opponents agreed that their eight years in the Governor's mansion in Cheyenne had been highly successful. There were nearly as many Republican opponents as Democrats at the farewell dinner for 600.

Sullivan's friend, US Attorney David Freudenthal, who brought him into politics, had to remind him: "This is not a retirement dinner. You are about to be unemployed and evicted from your residence."

Joking about Sullivan's reputation for not compromising on his principles during his term of office, Freudenthal told the guests: "You have no idea how annoying it is to have so much virtue around all the time."

Other Democrats recalled how Sullivan refused to let the party bosses run a mud-slinging campaign to counter the Republicans' jibes at his friendship with Clinton. But Democrats were not too happy when Sullivan as governor abandoned the usual party political "spoils system" and appointed people to office on merit rather than affiliation.

He is given credit for getting Wyoming through a tough economic period when falling oil prices and a slump in agriculture badly affected the state's two main resources. He was re-elected for a second term with a record vote, which meant that many Republicans switched sides to support him.

Sullivan's battered stetson, which he bought in 1968, became his trademark on the campaign trail. It has become so famous that he has donated it to the Wyoming State Museum.

The local Casper Star-Tribune ran a funny account of Sullivan's hat telling its own story from the time it became "the perfect mate for his follicularly impaired pate". It included an actual letter to the paper in which a reader said he was disgusted at seeing Sullivan on national TV wearing his "filthy, ratty hat" when Wyoming was playing at a big football game in San Diego. This started a long correspondence between supporters and critics of the battered hat.

Before he went back full-time into his law practice, Sullivan took up a fellowship for a term to teach at the Kennedy School of Government at Harvard. He and Jane also enjoyed attending lectures at the famous university and it brought back memories of their days at the University of Wyoming, where they met and where he won a degree in petroleum engineering and a doctorate in law.

The reports that Sullivan is a front-runner for US ambassador to Ireland have caused a stir in Wyoming, a sparsely-populated US state and not used to its sons gracing the diplomatic salons of the world. Democrats and Republicans are calling to wish him well.

Al Simpson believes he is ideally suited for the job. He has known Sullivan and admired him as a skilled lawyer, lobbyist and politician for over 30 years. "I have seen him at work. He is very thoughtful, very thorough, much like a George Mitchell - patient and partisan but never lets his partisanship interfere with his effectiveness."

Jane Sullivan has also won kudos with the people of Wyoming for her work in the Governor's mansion promoting worthy causes and the arts. She is passionate about wild flowers and brought national experts to Wyoming to help promote the state's natural vegetation.

The Sullivans are both devout but unobtrusive Catholics. Mike Sullivan has pointed out that his Catholicism has not prevented him refusing to commute the death sentence on a notorious killer executed in 1992 - the first execution in Wyoming in 36 years. On abortion he is generally opposed, but not in all circumstances.

His Irish forebears from Cork emigrated to the US around 1850 and made their way across the country to the copper mines in Michigan. His grandfather qualified as a lawyer and moved to Wyoming. On his mother's side, he is descended from a Geraghty from Co Longford who made his way to the US back in 1856. It looks as if he will soon be able to trace those roots in person.