OTTAWA - Almost every moment of this campaign, Stephen Harper was the congenial, sweater-vested uncle who spoke constantly about his family and projected an unwaveringly sunny disposition.

It was the moment he strayed from the script that might have cost him a Conservative majority government.

In that brief instant Harper dropped the gloves, tossed aside the metaphorical sweater-vest, and took a swipe at artists as rich elites who were somehow unlike normal Canadians.

It's hard to gauge the precise impact of those words but they coincided with a Conservative slide in the polls in Quebec, the province that was supposed to serve as the building block toward a majority.

The Liberals have spent the last three election campaigns trying -- in the words of one Paul Martin aide -- to "make Stephen Harper angry."

They never succeeded in 2006 and failed again in 2008. This time, Harper managed to sound grumpy without any help from his political opponents.

Harper is occasionally a one-man study in contrasts.

Like the political Kodak moment two years ago in which Harper's two sides -- the cool, cerebral strategist and the hot-tempered partisan -- were on full display in a single snapshot of the prime minister at his best and his worst.

In that snapshot moment two years ago he was decisive, bold and fast-moving.

He was also crabby, coarsely partisan and somewhat disingenuous as he blamed the opposition for his sudden decision to break an election promise.

As part of his pledge to clean up federal politics, the Conservative leader had said he would create a new appointments commission to help combat political patronage.

The opposition rejected his first choice to lead the commission, Calgary oilman and Conservative backer Gwyn Morgan.

So Harper strolled downstairs from his office and, in the time it took him to enter the House of Commons, casually announced that there would be no commission.

"We won't be able to clean up the (appointments) process in this minority Parliament," Harper said.

"We'll obviously need a majority government to do that in the future."

The prime minister's fans and foes can find in that episode evidence to support their differing views of the man.

In 2006, he won plaudits and nourished a reputation for decisiveness by campaigning on a pledge to implement a simple, tightly focused list of five easy-to-remember priorities.

He has since made a series of sudden, controversial moves that stunned his opponents: recognizing a Quebecois nation within Canada, taxing income trusts and calling a quick vote in the Commons to prolong Canada's Afghanistan mission.

Then, just five weeks ago, he triggered a new election despite his own fixed-election law that promised a campaign in late 2009.

His detractors see him not as a man of decisive action but as a leader who is prone to petulant outbursts, who flip-flops and breaks his word, who is far better at strategizing against real and perceived enemies than he is at making friends.

Even the announcements on the Quebecois nation and the Afghanistan vote seemed inspired more by a desire to embarrass the Liberal party than by conviction.

On Quebec, he had refused for months to describe the province as a nation -- but began singing a new tune the week of a convention where the Liberal party seemed destined to tear itself apart over the issue.

On Afghanistan, he campaigned on a promise to let Parliament vote on all future military deployments. But just before the Afghan vote he told stunned MPs he'd simply ignore the result if they voted against the mission.

Some politicians will agree to meet with protesters, either to calm tensions, learn about an issue or just for the publicity. Not Harper. His reaction to demonstrators at a Three Amigos summit with the U.S. and Mexican presidents was to label the protesters "pathetic."

His hostility toward opponents knows no geographic borders. While most leaders put domestic trash-talking aside when they're travelling abroad, Harper revels in it.

Standing near the former site of the Berlin Wall last year, he appeared to draw parallels between the collapse of communism and the end of 12 years of Liberal rule in Canada.

One Conservative who has worked closely with Harper on two election campaigns says he's not the first cut-throat partisan to occupy the prime minister's chair.

"Chretien was just as bad -- and so was Mulroney," said the high-ranking Tory.

"But what they had was the political maturity not to show it. They knew there's a time and a place to be overtly partisan. Stephen has a bad sense of timing on that."

An example came in the final days of the 2006 campaign.

With a majority government within reach, Harper suggested he would be prevented from making drastic changes to the country because Liberal senators, judges, and civil servants would keep him in check.

The final days of the campaign were hampered by what resembled a partisan broadside against tens of thousands of people. That simple musing might have cost him a majority government.

But that self-inflicted damage was nothing compared with the previous election.

In 2004 the Conservative leader came within a hair's breadth of power and fell short, perhaps due to an extended temper tantrum during the campaign's final week.

As media coverage got more critical and he became increasingly annoyed with questions about abortion and same-sex marriage, he retreated to safe Alberta ridings and stopped holding news conferences.

The cruel irony for Conservatives was that, by going silent, Harper deprived his party of its most effective salesman.

The prime minister communicates clearly, rarely stumbles while speaking, and is a quick-witted and clever debater. But in 2004, he picked up his ball and went home a few days early.

In the meantime, a cheerful Paul Martin criss-crossed the country in an energetic bid to save as many Liberal ridings as possible. Liberal numbers improved in the final days and Harper remained in opposition.

Conservatives say that after the 2004 debacle the party's current campaign chair was among several prominent Tories who shared a tough assessment with Harper.

"'Look Stephen, you cannot do this'," was how one source characterized Doug Finley's message to the leader.

"'You can't sit on a bus and sulk. You can't put yourself in a bubble.

"'If you want to win, this is what you've got to do: You've got to put a smile on your face, put up with all these people, get out there, get over your self-centredness, and reach out'."