OTTAWA - It's as if a curse hangs over Canadian politics, dooming any effort by a premier to make it as prime minister.
Should departing Ontario Premier Dalton McGuinty decide to run for the federal Liberal leadership, he's likely to run smack into that political quirk.
Plenty of federal MPs or cabinet ministers have become premiers. Jean Charest in Quebec; Brian Tobin in Newfoundland and Labrador; and Bob Rae in Ontario all made that transition in recent years.
And Hugh John Flemming went from New Brunswick premier in 1960 to federal cabinet minister in the John Diefenbaker Conservative government.
But moving from the premier's office all the way to the prime minister's office hasn't worked in more than a century.
Sir John Thompson, prime minister from 1892 to 1894, had been premier of Nova Scotia for less than two months in 1882. Sir Charles Tupper was premier of Nova Scotia for three years from 1864 to 1867, and became prime minister briefly in 1896.
They were the last and only premiers to have made the successful transition to federal power.
It hasn't been for lack of trying.
Between 1942 and 1976, the Conservatives chose three successful provincial premiers as party leaders: John Bracken of Manitoba, George Drew of Ontario and Robert Stanfield of Nova Scotia.
They were proven winners. As Nelson Wiseman, a political science professor at the University of Toronto, points out: "When he became leader, Bracken was the longest-serving first minister in the British Empire."
But all three fell short of the big prize. Stanfield came close, losing by a whisker to Pierre Trudeau in 1972.
The NDP tried their luck with Tommy Douglas, the legendary CCF premier of Saskatchewan. Their best showing under Douglas was 22 seats in the House of Commons.
Rae, who went from New Democrat MP to New Democrat premier in Ontario in 1990, and lost a bid for the federal Liberal leadership in 2006, says it's an exaggeration to say there's a curse on premiers who want to be prime minister, but it is true that making the transition is difficult.
"I still believe it's entirely possible that someone can have served as a premier and then become prime minister, but for some reason it's proven difficult," he said.
Part of it may be that premiers are identified with their province, not the country as a whole.
"When you become a premier, your obligation is to the people of your province and your obligation is ultimately to defend the interests of your province, and sometimes to take positions which might seem antithetical to other regions of the country," he said.
"That might be a factor."
In the 1980s, for example, then Ontario premier Bill Davis was seen as a potential Tory leader. Rae said he still regrets that Davis ultimately didn't run.
But, he acknowledges, Davis would have had some troubling baggage.
"There were regional issues at stake and his position on the Constitution, his support on energy issues, I think, made it harder for him to get support in Western Canada.
"And obviously if you want to become prime minister you need to have support in all parts of the country."
Those problems applied in reverse to Alberta's Peter Lougheed, also seen by some as a potential federal Conservative leader.
Wiseman said, however, that premiers have tended not to seek a federal leadership. "One of the things that's happened here is that we haven't had many premiers that have run."
It's been 40 years since Stanfield. In between, Davis, Lougheed, Tobin, and Bernard Lord and Frank McKenna of New Brunswick, were all touted at times as potential federal leadership candidates, for one party or another, but backed away.
In the United States, governorships are seen as stepping stones to the presidency. Most recently, it worked for George W. Bush of Texas, Bill Clinton of Arkansas, Ronald Reagan of California and Jimmy Carter of Georgia.
Wiseman said that has more to do with the American presidential system, with its state primaries and state delegations that can be important for governors, especially those from large states.
Canadian premiers may have more power than the average governor, but the electoral systems are different.
Despite the historical record, Rae said, things can change for premiers who want to be prime minister.
"It is not a hard and fast rule and we will one day, I predict, see the rule broken, but it's certainly proven to be a pretty enduring tendency in our national politics."
Note to readers: This is a corrected story. An earlier version had the wrong last name for Frank McKenna