The incumbent British Columbia Liberal Party, under the leadership of premier Christy Clark in her first provincial-wide election, has held on to power for a fourth consecutive government, despite the fact that the British Columbia New Democratic Party was heavily favored throughout the campaign to win the election.

This was definitely a surprise, given that the BC NDP was leading by nearly 20 points two months ago, and even though polls showed a narrowing race in Canada’s third-largest province, forecasters still believed the BC NDP a heavy favorite just a day ago that showed a narrowing race in Canada’s third-largest province.  No poll showed the BC Liberals leading this race, though polls showed Clark narrowing the gap against BC NDP opposition leader Adrian Dix.

As of around 1:15 am EST on Wednesday morning, the BC Liberals have been elected to 45 seats and were leading in 51 seats, while the BC NDP had been elected to 27 seats and leading in just 32.  Andrew Weaver was set to become the province’s first Green Party legislator, with one independent rounding out the membership of the 85-seat provincial assembly.  Given that the BC Liberals held 45 seats going into the election and the BC NDP held 36 seats, the BC NDP may well have lost seats on Tuesday.

In particular, former Vancouver mayor from 2005 to 2008, Sam Sullivan, was handily elected to a seat in the Vancouver-False Creek riding for the BC Liberals.  Clark was leading, just slightly, in her own constituency in Vancouver Point Grey against a strong challenge from the BC NDP’s David Eby (NB: if Clark doesn’t win, it’s expected that a colleague will step down to allow Clark to win a speedy by-election).

It’s, of course, really bad news for Dix, whose leadership should almost certainly come to an end with Tuesday’s disastrous result.  It’s really bad news for Thomas Mulcair, the opposition leader of Canada and federal NDP leader, who had embraced Dix and the provincial NDP in a way that federal Liberals had not embraced Clark and the BC Liberals.

It’s the second upset in as many years in western Canada — in Alberta in April 2012, nearly every pollster showed that another longtime incumbent party was set to lose power.  But Alison Redford, the beleaguered incumbent premier, led her Progressive Conservative Party to victory against a challenge from Wildrose, a new party that had run both to the social and fiscal right of Redford.

So how did the BC Liberals do it?  Here are four reasons that explain what happened Tuesday in British Columbia.

Business interests and others feared the economic consequences of an NDP government.

Dix, who started off the campaign with essentially platitudes, never found a way to reassure business interests in British Columbia that he would facilitate economic growth in the province.  Dix won the BC NDP leadership election in 2011 narrowly against Mike Farnworth with a more stridently leftist tone, and that progressive perspective may well have made the party less palatable as voters focused on their own economic interests in the month leading up to Tuesday’s election.

Nowhere was this clearer than in his opposition not only to the proposed Northern Gateway pipeline, but also to the Kinder Morgan pipeline expansion that would triple the oil flow from Edmonton to Burnaby (just east of Vancouver).  Although he may have attracted the support of environmentalists, his stance scared business interests and also voters who see both pipelines as a way of obtaining a share of western Canada’s oil wealth.  One headline even argued that Dix would return British Columbia to ‘the dark ages’.

In a world where economic growth throughout the developed world globally remains weak, pledging to make your constituents poorer and to push jobs away is never a great position to take in any campaign.

Clark ran a tough campaign against Dix and it worked.

In a race where Dix had literally a new BC Liberal scandal to choose from every day, he remained essentially true to his word to run a positive campaign.  That remained true even despite the fact that voters believed that the incumbent BC Liberal government was thoroughly exhausted and corrupt and even after Clark spent a week in late April apologizing over running a red light.

Not only did Dix run a positive campaign, but he failed to respond adequately to the aggressive campaign the BC Liberals ran against him, essentially scaring voters that Dix would be bad for the province’s economy. Clark both managed to paint the charmless Dix simultaneously as a wishy-washy ‘weathervane’ and a threat to British Columbia’s economy — check out this ad:

Her campaign also brought up the specter of the previous BC NDP government, which magnificently lost power in the 2001 elections that saw the BC Liberals, under former Vancouver mayor Gordon Campbell, win 77 out of 79 seats.  The BC Liberals, under Campbell through 2011 and under Clark thereafter, have been in power ever since.

BC Conservatives rallied around the BC Liberals.

As results came in early Wednesday morning on CTV, the former federal of the Canadian Alliance, Stockwell Day, who preceded Stephen Harper as the leader of that party before its alliance with the Progressive Conservative Party to form today’s Conservative Party in Canada, was on the air as a Clark campaign strategist.

In the leadup to the election, the British Columbia Conservative Party was winning up to 20% to 23% of the vote in polls last summer and it appeared that, for the first time, the BC Conservatives would be more than just a fringe movement.  In March 2012, John Van Dongen, a Liberal MPA, had defected to the BC Conservatives, giving the party its first member of British Columbia’s provincial assembly in recent memory.  But Van Dongen thereupon defected from the BC Conservatives later in September 2012 to sit as an independent.  BC Conservative support had fallen into the low double digits by the time the campaign kicked off in April.  Its leader, John Cummins, ran an unimpressive campaign, and he turned in a less than impressive performance in the leaders’ debate. By and by the end of the campaign, the BC Conservatives had fallen well below 10% and into the single digits.

So as Tuesday approached, natural Tories rallied behind Clark and the BC Liberals, if for no other reason to support the more pro-business of the two realistic winners of Tuesday’s election and to keep the BC NDP out of office.  This isn’t unlike what happened in last year’s Alberta election, where natural center-left and progressive voters rallied behind Alison Redford and the Progressive Conservative Party in Alberta in order to keep the more socially conservative Wildrose out of power.

Justin Trudeau.

No one in British Columbia would admit it, and I’m sure all of my friends in British Columbia would decry it, and even two months ago, I would have scoffed at it.  After all, the first rule of Canadian politics is that federal politics and provincial politics are very much separate.  The federal Liberal Party is very much a different beast than the British Columbia Liberal Party or the Ontario Liberal Party or the Parti libéral du Québec (PLQ, Liberal Party of Québec).

But there’s no doubt in federal polling that the election of Justin Trudeau last month as the new leader of the Liberal leader has breathed new life into a brand that had decayed nearly to the point of extinction.  The Trudeau-led Liberals have gone from third place in national polls to being tied with or even leading the incumbent Conservative Party, with Mulcair’s NDP falling far behind in third.

Now that may be a temporary, stratospheric blip for Trudeau, who will never be as novel, generic or popular as he is in the honeymoon days following his federal Liberal leadership victory.  But even in Québec, the PLQ has jumped to a lead of 38% to just 25% for the incumbent sovereigntist Parti québécois (PQ), and I find it hard to believe that the election of Philippe Couillard as the new PLQ leader is enough to turn a double-digit swing in the past month.  But it’s hard to think that Trudeau’s rebranding of the Liberal name didn’t put at least a little shine on the BC Liberals, pushing perhaps even a handful of BC NDP supporters back to the BC Liberals.  Maybe, maybe not.

Trudeau didn’t provide any material help to Clark (though Mulcair endorsed Dix), and it’s not nearly as important a factor as the other three, but I think it is a small factor nonetheless.