Manitoba Premier Gary Doer announces his intention to step down from office as his wife, Ginny Devine, looks on Aug. 27 in Winnipeg. The NDP is selecting a new provincial leader this weekend. (CBC)

Gary Doer, Canada's longest-serving current premier, formally steps down Saturday when New Democrats elect a new Manitoba leader this weekend in Winnipeg.

His departure is being mourned not only by party faithful in Manitoba who have him to thank for three majority governments, but by New Democrats across the country who view him as proof that a left-wing party can govern successfully and appeal to white-collar, upper-class voters.

Doer, 61, earned the nickname the Teflon premier because it seemed nothing bad would ever stick to him.

'The tough day for me was announcing I was stepping down. Once I crossed the Rubicon, I crossed the Rubicon. I feel very confident that I made the right decision.'—Gary Doer, outgoing Manitoba premier

The provincial NDP leader since 1988 and premier since 1999 surprised many political observers by announcing Aug. 27 that he would be stepping down. The following day, he was introduced in Ottawa by Prime Minister Stephen Harper as Canada's next ambassador to the United States.

If the man who vowed never to be a "lifer" at the legislature has any regrets about quitting and accepting the ambassadorship, he's not sharing them.

"I've been going through my to-do list," Doer said in a recent interview. "I really haven't spent a lot of time on nostalgia or anything else. The tough day for me was announcing I was stepping down. Once I crossed the Rubicon, I crossed the Rubicon. I feel very confident that I made the right decision."

Doer's departure, which shocked observers and supporters, comes well before the 2011 election with the New Democrats riding high in the polls. He helped build the party on personal charm and charisma, leaving even hockey commentator Don Cherry confused at a recent meeting about whether "to kiss him or shake his hand, he's so good-looking."

'He showed that Democrats bring good government.'—Jack Layton, federal NDP leader

Doer was as much at home at a Chamber of Commerce luncheon as he was in a union hall, something political strategists credit for his success.

Paul Thomas, a University of Manitoba political scientist, said Doer made Manitoba a big player on both the national and international stages.

Doer "worked intergovernmental connections very effectively and gave Manitoba actually more clout than they might deserve as a small, have-less province in the middle of the country," said Thomas.

Changed image of NDP

Observers say he changed the image of the NDP in Manitoba from a "tax-and-spend party" to one that supports lowered business taxes and bolstered social spending, and has balanced the books 10 years in a row.

"He showed that Democrats bring good government," said federal NDP Leader Jack Layton. "People may have forgotten that Tommy Douglas ran 17 balanced budgets in a row and did wonderful things around economic development, the environment, social justice and health care.

"Gary Doer has now reminded Canadians of what New Democrats can do in all of these fields, while at the same time living within the means of the population."

Doer's example has been most recently copied by Nova Scotia's Darrell Dexter, who came into power last summer. Dexter said he was in Manitoba working on Doer's campaign in 1999 when the party won its first majority.

"I followed what he was doing and the approach that he took pretty carefully," Dexter said in an interview. "I was always very impressed by his ability to build a big-tent approach to politics so that people who might not always consider themselves to be New Democrats did consider themselves to be New Democrat voters."

Manitoba federally Conservative

While federal NDPers may hold up Doer as a model, his approach hasn't done much for the party in Ottawa, said political scientist Richard Sigurdson.

Manitoba is largely a Conservative province federally, despite Doer's popularity.

"It's a model that only really works within specific provinces," said Sigurdson, dean of arts at the University of Manitoba.

'The people of Manitoba … should have a great deal of pride in how he conducted himself and represented the people of Manitoba.'—Dalton McGuinty, Ontario premier

Doer was first elected in 1986 and joined the NDP cabinet. He became party leader two years later following the defeat of then Premier Howard Pawley.

Doer led the party from the Opposition benches for 11 years before winning the first of three consecutive majority governments in 1999.

Before becoming a premier who pushed education as a key to economic success, Doer was a university dropout and a guard at a youth jail in Winnipeg. He rose to the head of the powerful Manitoba Government Employees Union before entering politics.

Although many feared a former union leader would have an uneasy relationship with business, Doer straddled the two worlds successfully. He lowered business taxes and refused to pass legislation that would ban replacement workers in the event of a strike.

"The people of Manitoba … should have a great deal of pride in how he conducted himself and represented the people of Manitoba," said Ontario Premier Dalton McGuinty, who has worked alongside Doer at premiers meetings since 2003.

"I'm not sure Prime Minister Harper could have made a better choice [than] Gary Doer as our newest ambassador in the United States."

Doer's heart remains in Manitoba

While he is leaving his job in Manitoba, Doer said he would always be part of the province.

"I'm not selling my home or my cottage," he said. "The job is great in Washington. It's very challenging representing Canadians — the good story Canadians have to tell in Washington.

"But my home and my friends are here."

A farewell dinner for Doer will be held at the Winnipeg Convention Centre Friday night. But he has little time to spend basking in accolades.

A party leadership convention takes place Saturday in Winnipeg, where hundreds of delegates will choose a new leader — and premier — from either Thompson MLA Steve Ashton or St. Boniface MLA Greg Selinger.

Results should be known by about 4 p.m. CT, said Lorraine Sigurdson, president of the Manitoba NDP.

After a "transition day" on Sunday, Doer plans to arrive at work at the Canadian Embassy in Washington on Monday.

His pragmatic approach will no doubt come in handy in diplomatic circles. But the man who once called the United States "the real villain" in a environmental tussle over a North Dakota lake admits he may have a challenge keeping his tongue in check.

"I know I can't have some of the same latitude on what I say, but I don't have any difficulty with that. I may use the odd colourful term but … I will be disciplined in the job I have in the future."

With files from The Canadian Press