Stephen Harper was elected the first leader of the newly formed
Conservative Party of Canada on March 20, 2004. He edged out
Belinda Stronach and
Tony Clement on the first ballot and was reinstated as the leader of
Her Majesty's Loyal Opposition in the Canadian House of Commons on March 22, 2004. He was sworn in as prime minister after his party won a minority government in the 2006 Canadian eederal election.
Harper first became the Leader of the Opposition in May, 2002, when he defeated Stockwell Day to become the leader of the now defunct Canadian Alliance. The possibility of a merge between the Alliance and the Progressive Conservative Party of Canada had been discussed but former PC leader Joe Clark resisted. The political differences, however subtle, between the Alliance and the Progressive Conservatives sparked concern among many Tories. Some didn't want to be associated with the Alliance, the party furthest to the right in the Canadian political spectrum.
After Clark stepped down as leader, new PC leader Peter MacKay and Harper worked out a deal that would dissolve their own parties and form the Conservative Party of Canada. Both parties voted overwhelmingly in favour of the merger.
Harper announced his candidacy for the party's leadership shortly after. MacKay chose not to run. Former Ontario MPP Tony Clement and former Magna CEO Belinda Stronach entered the running.
Media coverage of the campaigns rarely focused solely on Harper. Stronach, who entered the race despite having no political experience, became a media darling (most likely due to her age, gender and financial situation).
In order to combat his previous "invisible man" image (as mentioned by Dave_Littler), Harper tried to become more of a public figure during the campaign. He tried to build a "family man" image for himself, and began to mention his wife and children in his political campaigns for the first time. Despite this, he claimed he wasn't going for an all-out makeover (see Preston Manning).
Harper was frequently quoted as criticizing Stronach's lack of experience and lack of fluency in French. He did, however, thank her during his victory speech for generating interest in the race, adding that she generated "more glamour" than he could have.
Harper continues to push for a federal election this fall, and is still of the opinion that Canada would benefit from a fixed election schedule (like that of the United States).
Under Harper, the united Conservative platform would include upper class tax cuts, reduced support for marriage for same sex couples (many Conservatives support civil unions instead). Harper says he supports the "traditional definition of family" (which probably means the traditional definition of marriage) but hasn't really expanded on it. Harper said that, if elected, he would not leave the issue up to the Supreme Court of Canada but would allow it to be decided by a free vote in parliament.
Harper's victory could not come at a more important time in Canadian politics. The country is divided on issues including same sex marriages and the current sponsorship scandal plaguing the Liberal government (the auditor general alleges the government misused millions of public dollars). The questions are whether Harper can shed his far-right image and whether Canada's progressive voters are ticked off enough at the Liberals to vote for Harper.
The Liberal Party won a minority government in the 2004 Canadian Federal Election; Harper expressed disappointment with his apparent inability to make a breakthrough (especially in Ontario and in Atlantic Canada) but seemed pleased that his party had stripped the Liberals of the majority rule they'd held for eleven years. Harper could thus serve another term as the leader of the opposition, but a recent interview indicates that he's considering stepping down as leader of the party. He later said he would probably be staying on as leader.
The Conservative Party of Canada won a minority mandate in the 2006 Canadian federal election. Harper was sworn in as the country's 22nd prime minister on February 6, 2006.