Because that's not the OP. I also knew TM would react in precisely this manner. Perhaps the next thread should be "PM Preston Manning."

If someone answers the OP well enough, I just might write a mini-TL on a Harris PMship.
Well to get rid of Chretien, you'd need a perfect storm: A major scandal that directly implicates Chretien in criminal/highly unethical action; A 'united right' (or at least one that isn't engaging in fratricidal behaviour); A resurgent NDP; And a competent opposition leader.
Here's an attempt:
Say Adscam hits full force in 2001 or 2002 coupled with something similar to the alleged inside trading on imcome trusts that resulted in an RCMP investigation of the Finance Minister in the middle of the 2006 election campaign. Having Martin also be accused of corruption will make things even better for the Tory Alliance. Combine this with angry Liberal MPs who weren't connected to Adscam yet are going to be the ones who pay for it, and with the feud between Chretien and Martin, and the Liberal party rips itself apart at the worst possible time.
Follow this with an opportunistic reunion of the Tories and the Canadian Alliance. The Tory backroom smells Liberal blood and dumps Clark. The Alliance backroom/grassroots does the same to Day. The now reunited Conservative Alliance pretty much begs Harris to become their leader, and unlike OTL, he accepts, mostly due to the fact that the CA has a real chance at victory in the forthcoming election.
The NDP has been slowly recovering from the repeated thrashings they took throughout the '90s. Jack Layton is an inspiring though risky choice as leader, but when (super)Adscam blows, Layton seizes the opportunity to carve chunks out of the Liberal party's base support. Support for the NDP slowly but surely rises back to where it was in the late 1980s.
For the BQ, Adscam is like Christams come early, only better. After years of slow erosion, support for the BQ rises back to levels unseen since the 1993 election. The only worry the BQ has is that Tory support was also on the rise, mostly in rural ridings near Quebec City and in those in Quebec City itself.
As the last federal election was in November of 2000, Chretien does not have to call another one until 2005. Holding off turns out to be a fatal mistake. Had Chretien called an election immediately, he might have survived as the opposition was still in disarray at the time. Instead he gave the Tories and the NDP more than three years to get their act together. The 2005 election in marked as being one of the dirtiest in Canadian history. And when it is over, the result is on par with 1984 or 1993. Chretien's government is thrashed, not just defeated.
In 2000 the Liberals won 172 seats. In 2005 they've won a mere 35. Even 1984 wasn't this bad. Not a single Liberal MP is reelected in the province of Quebec. Both Jean Chretien and Paul Martin have gone down to a humiliating defeat.
In 2000 the NDP had won 13 seats. In 2005 they've won 45, including two in Montreal.
In 2000 the BQ had won 38 seats. In 2005 they've won 57. In a perverse twist, the BQ has become the "Loyal Opposition" for the second time in their decade and a half of existence.
In 2000 the Canadian Alliance won 66 seats and the PCs won 12. Going into the election the combined party had held 84 seats, including several they'd picked up in by-elections in 2003 and 2004. When the dust settles ofter the 2005 campaign, the united Tories have nearly doubled that, winning 164 of the 301 seats in parliament. Sixteen of their seats come from Quebec, where Tory candidates have defeated 14 BQ and two Liberal MPs.
Even as the last votes are being counted in Alberta and British Columbia, Mike Harris is celebrating his unprecedented victory. Before him, not one of Canada's Prime Ministers had first been Premier of a province. Tories of all stripes are celebrating their first real victory in more than a decade.
Liberals are too stunned to respond, not really able to comprehend what just happened.
The NDP feel that they've won a great victory, even if "Chainsaw Mike" is now PM. In the eyes of the NDP and the activists who support it, Mike Harris reactionary as he is, isn't a crook. They can live with him, especially if he finishes gutting the Liberal party and thus leaves the NDP as the only credible, national alternative to the Tories.
The BQ (and the PQ in Quebec City) are optimistically counting down the days until the next sovereignty referendum, to be held not long after Jean Charest and the LPQ lose an election in Quebec.