Now that Justin Trudeau and the Liberals have won the federal election, we will soon see whether our new government will follow through on its campaign promise to legalize marijuana and remove possession from the Criminal Code.

Ten years ago, before the Harper years, the nation seemed poised to revise its position on marijuana prohibition. In fact, it seemed like a foregone conclusion that something was about to change, as the debate at that time often focused on decriminalization versus outright legalization.

However, the Liberals' attempts at decriminalization didn't sit well with our American neighbours, who were vehemently opposed to such action back when George W. Bush was president.

Legalizing marijuana could bring significant benefits, including tax revenues for the federal government, David Garvey says. (Pawel Dwulit/Canadian Press) When Mr. Harper and the Tories took the reins in 2006, all the talk about repealing prohibition disappeared like a puff of smoke with his tough anti-drug strategy.

But the issue did not really go away in either Canada or the U.S., and in 2012, voters in the states of Colorado and Washington moved to legalize recreational cannabis sales, with more people in Colorado coming out to support the repeal of prohibition than did for President Barack Obama.

M arijuana stores outnumber Starbucks

Coloradans then turned their already thinly veiled medical marijuana dispensaries into full-blown retail outlets available to anyone over the age of 21. Recreational marijuana dispensaries now outnumber the state's Starbucks locations. Canna-business is booming.

A decade prior, it would have seemed inconceivable that an American state would act unilaterally against the federal government to repeal marijuana prohibition while Canada moved in the opposite direction.

Yet that is exactly what happened. Mr. Harper, ignoring scientific facts and all of the available current data, decided to show he was tough on crime and not only dismiss any notion of repealing prohibition, but actually toughen the existing penalties for those caught selling or growing the forbidden plant. Because leadership! And why miss an opportunity to align our policies with those of the Bush administration?

Colorado and Washington served as guinea pigs for this new approach to marijuana in the U.S., escaping interference from Obama's justice department; other states, such as Oregon and Alaska, have followed suit. The tide of public opinion is turning.

We know the results of the great Colorado weed experiment, and, generally, things have been just fine.

Colorado reaps tax rewards

The old line on the dangers of marijuana was proven false years ago anyway. Denver has not turned into a zombie town filled with witless stoners. Crime hasn't gone up, kids aren't dropping out of school, and the gateway argument should finally be laid to rest, as pot smokers have not all suddenly turned to heroin.

Rather, the state's economy has been given a real shot in the arm, with massive tax revenues that have been earmarked for public schools, medical marijuana research and costs associated with marijuana legalization. In the first year of legalized weed, the state brought in $76 million U.S.; in 2015, it made nearly $73.5 million by the end of July. In Oregon, $11 million worth of retail weed was sold in just the first five days after repealing prohibition, Time reported.

As is the case with Amsterdam, many people have started travelling to Colorado for a chance to legally spark up -- a whole new brand of cannabis tourism.

Winnipeg city council decided to get ready for the inevitable legalization even before knowing the results of the federal election.

It makes one wonder what could have been. What if Manitoba had acted unilaterally on this issue back in 2006? How much tax revenue could have been collected if we had been the first? Maybe we could have started fixing all of our crumbling roads years ago.

Ridiculous political calculation

Surely, in preparing for this election, Mr. Harper must have considered the tax revenue lost through his misguided policies and wondered if his purely political stance had been wrong all along.

Most telling was the wording of the Conservatives' own ubiquitous advertising during the election: "Legalizing marijuana, is that really our biggest priority right now?" asked the man in the rather infamous resumé commercial.

If you want to collect a new source of revenue that can be invested back into the community and stop needlessly wasting time and money on prosecution, then yes, legalization should absolutely be a top priority right now. The very way the question was framed in the commercial indicated that the Harper policy was nothing more than a ridiculous political calculation, at odds even with his preposterous statement that marijuana is infinitely worse than tobacco.

We can look to Colorado, Washington and Oregon and see that not only are responsible adults already deciding for themselves when it comes to recreational cannabis, it's also a burgeoning new industry.

Mr. Trudeau, please follow through on your campaign promise and correct a mistake that should have been fixed 10 years ago.

David Garvey is a Winnipeg writer.