A lot will be said in the next week about tonight's Liberal landslide in Canada's federal election.

Justin Trudeau's positive campaign style, his clear love for the country's diversity, the strength of Liberal candidates, and the people's desire to throw out Stephen Harper's Conservatives were all factors behind what happened.

But perhaps as much as anything, the Liberals' adoption of many evidence-based policies may have proven decisive.

The Liberals didn't fear that the electorate was too stupid to wrap its mind around complicated information.

Take the issue of supervised-injection sites.

The data from Vancouver's Insite facility is overwhelmingly positive.

More than two dozen peer-reviewed studies show that the country's only legal supervised-injection site saves lives and money, cuts street disorder, and reduces the transmission of diseases.

Trudeau wasn't afraid to say that he supported building more of these facilities in Canada.

The same is true of the Liberals' approach to tax policy. The evidence is that too many tax breaks for the wealthiest members of society stymie economic development.

This is abundantly clear to anyone who's read the work of progressive thinkers like former U.S. secretary of labor and economist Robert Reich, Liberal MP Chrystia Freeland, and even author Linda McQuaig, who failed to capture a seat for the NDP in Toronto this election.

Yet it was the Liberals, not the New Democrats, who were more aggressive in dealing with personal taxes.

"We will cancel income splitting and other tax breaks and benefits for the wealthy," the Liberal platform declares.

The Liberals promised to increase the marginal federal tax rate from 29 percent to 33 percent for those with taxable incomes over $200,000.

The marginal federal rate for those with taxable incomes between $44,701 to $89,401 will fall from 22 percent to 20.5 percent.

These changes were touted as "revenue-neutral".

The party is also going to adjust Canada's child-care benefit, unlike what was promised by the Conservatives and the NDP. The Liberals say they'll phase it out entirely for high-income earners.

This reflects the growing realization that the economic slowdown in the western industrialized world is really linked to a shortage of demand for goods and services. Anyone who's read articles by Nobel Prize–winning economist Paul Krugman knows that.

Redistributing tax benefits to the middle class and lower-income Canadians is an appropriate response to the problem.

Trudeau was also willing to run deficits in order to jack up spending on infrastructure, including rapid transit. It makes sense in a country with low interest rates and where 81 percent of residents live in urban regions. Investments in infrastructure will yield long-term economic dividends.

The Liberal platform was ranked second best, only behind the Greens, by the Council for Canadian Urbanism. It gave Trudeau's party 11 "very strong" and three "strong" ratings in its 14 categories.

Similarly, the Liberals were prepared to make major investments in arts and culture, which forced the NDP to play catch-up during the campaign. Trudeau pledged to double annual expenditures on the Canada Council of the Arts from $180 million to $360 million and boost spending on Telefilm Canada and the National Film Board by $25 million per year.

He also called for $150 million per year in new funding for the Canadian Broadcasting Corporation.

The creative economy is often overlooked by political parties, even though it has become a lifeblood of cities. Digital entrepreneurs, the performing arts, film production, and the music industry are major employers and their work helps drive tourism and economic growth. Trudeau seems to recognize this.

In addition, the Liberals were correct to move more decisively than the NDP on marijuana. While the New Democrats talked about increasing the number of police in Surrey, the Liberals pledged to legalize pot.

The war on drugs has led to widespread carnage, just like Prohibition of liquor fuelled the growth of U.S. organized crime in the roaring '20s. 

Trudeau looked at the evidence (egged on by Vancouver Quadra Liberal MP Joyce Murray) and called for the legalization of cannabis. Anyone who's paid attention to the health benefits of this plant knows that this is a no-brainer.

There is still room for the Liberals to pay more attention to scientific evidence, particularly when it comes to rising greenhouse-gas emissions. On this issue, the NDP had a better platform and the Greens had the best.

The Liberals' Murray, again, has been on top of this issue. But many of her fellow party members aren't as keen to look in a clear-minded way at the climate crisis, radically crank up federal support for renewable-energy options, and make carbon pricing a higher priority. The vagueness of the Liberal platform in these areas was revealed in an analysis by the B.C. Sustainable Energy Association.

Let's hope the next Liberal energy minister takes some time to look at the incredibly rapid growth of solar energy around the world.

But on the whole, the Liberals showed the most courage of the major parties in advancing potentially controversial policies. They didn't assume that voters were stupid.

And for this reason, among others, Trudeau has been rewarded with a majority government.