When the Liberals made Justin Trudeau their new leader, it was a high-risk, high-reward decision. His support for marijuana legalization is no different.

The potential reward in pursuing legalization is not insignificant. Increasingly, the three major parties differentiate themselves from one another only by degrees. But with the Liberals' new stance there is a stark contrast on what to do with the drug. New Democrats support decriminalization, while Conservatives are for the status quo. On this issue, the Liberals stand apart.

It allows the party to present themselves as forward-looking and in favour of smart-on-crime policies, as opposed to (what will undoubtedly be argued are) the timid and backward positions of the NDP and Tories. More importantly, it gives Liberals the potential to crowd New Democrats and the Greens out on this particular issue. NDP voters are, polls suggest, more likely to support legalization than decriminalization. And while the Greens support legalization, voters who feel this is an important issue may believe their vote would be better placed with a party that is more likely to be in a position to change the law.

Fishing in the Conservative pool of voters is certainly one aim of Trudeau Liberals — they have generally been more centrist on economic and fiscal issues — but the party will only win the next election outright if they can drive support for the NDP and Greens back to 20 per cent or less. This may be one way to do it.

Getting the youth vote to support the Liberals and actually head out to the polls is undoubtedly another part of the strategy, but there is no indication that middle-aged voters are any less supportive of legalization. It may not be a vote-driving issue for these Canadians, however. South of the border, it does seem that turnout was up in states where marijuana was a ballot issue. The goal may not be, then, to get younger voters on side with Liberals (it might be just as effective with older voters under the age of 55), but rather to give them a reason to get to the polls.

But will the legalization of marijuana be a major issue in the next federal election? That is where the risk comes in. It is hard to believe that 2015 will be the marijuana election, but Conservatives and New Democrats will almost certainly use it in their attacks against the Liberal leader. For the NDP, it gives them an opportunity to portray themselves as more reasonable and less radical than the Liberals, an essential strategy if they are to seriously challenge for government. With the NDP's more middle-way position on marijuana, Thomas Mulcair can pose as the responsible leader in juxtaposition to the inexperienced Trudeau's recklessness. The Liberal leader will need to flesh out the policy more during the campaign, and could be put on the spot on details.

For Conservatives, it is a perfect issue for their constituency. Their opposition to decriminalization or legalization puts them as the 'tough on crime' party. But while it may not be a number one issue for many, for those who are nevertheless uncomfortable with the idea of legalization — and these are primarily to be found among older voters who get out to the polls in big numbers — it could plant the seed of doubt that prevents them from casting a ballot for Trudeau.

The policy is a gamble that may or may not pay off in 2015. But the Liberals did not make Trudeau their leader to play it safe.

Éric Grenier taps The Pulse of federal and regional politics for Huffington Post Canada readers every week. Grenier is the author of ThreeHundredEight.com, covering Canadian politics, polls and electoral projections.

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  • In 2009, rookie MP Justin Trudeau votes for Bill C-15, which would have <a href="http://www.cannabisculture.com/content/bill-c-15-dead-now" target="_blank">imposed mandatory minimum sentences for marijuana-related offences. </a> The legislation passes the House of Commons with the support of both Tories and Liberals but dies after Parliament is prorogued.

  • In July of 2009, Trudeau is called a "f**cking hypocrite" by marijuana activist, the so-called "Prince of Pot" Marc Emery, who <a href="http://www.youtube.com/watch?v=5M-zSXF_dBU" target="_blank">claims the Liberal MP smoked cannabis with him four or five times</a>. "It really pisses me off when I see Justin Trudeau, who took big gaggers with me, is in Parliament actually voting for Bill C-15," Emery says.

  • In May of 2010, Trudeau tells Maclean's magazine that marijuana decriminalization is a step in the wrong direction. "It's not your mother's pot," <a href="http://www2.macleans.ca/2010/05/06/mitchel-raphael-on-what-justin-learned-from-his-whistler-days-and-a-helena-homage/" target="_blank">he tells Mitchel Raphael</a> of the stronger marijuana grown today. "I lived in Whistler for years and have seen the effects. We all need our brain cells to deal with our problems."

  • In an <a href="http://www.youtube.com/watch?feature=player_embedded&v=llTcoaBhU14" target="_blank">interview with ProjectRedDot</a> from the floor of the 2012 Liberal Convention in January, Trudeau says he understands pot is not as dangerous as other legal products like alcohol or tobacco, but expresses concern marijuana still "disconnects" you from the world. "So I don’t know that legalizing it – although I totally understand the arguments around removing the criminal elements – I don’t know that it’s entirely consistent with the society we’re trying to build," he says.

  • Seventy-seven per cent of delegates at the 2012 Liberal convention tell the party's leadership they want a future Liberal government to legalize marijuana. "Frankly, the status quo doesn't work and that's what needs to change," says <a href="http://www.huffingtonpost.ca/2012/01/15/liberal-vote-legalize-marijuana_n_1207388.html" target="_blank">interim Grit leader Bob Rae</a>. "The Liberal party is saying that the current laws do not work and that we need a new direction."

  • In November of 2012, not long after launching his leadership bid, Trudeau tells a group of Charlottetown high school students he is a <a href="http://www.huffingtonpost.ca/2012/11/14/justin-trudeau-marijuana-decriminalization_n_2129476.html" target="_blank">"huge supporter" of marijuana decriminalization.</a> "I think we have to recognize first and foremost that the war on drugs, as it exists right now, doesn’t work," he says, adding that the next logical step may be legalization.

  • In January of 2013, Trudeau <a href="http://www.reddeeradvocate.com/news/Marijuana_mental_health_among_Trudeaus_top_priorities_188676371.html" target="_blank">tells a crowd in Red Deer</a> that he would seek the full legalization of marijuana in order to tax and regulate it, making it more difficult for young people to access. "When it's illegal and only available in the black market, someone pushing it doesn't check for ID," Trudeau says.

  • In April of 2013, Trudeau speaks to party members at the Liberal leadership showcase. His speech, <a href="http://www.huffingtonpost.ca/2013/04/06/justin-trudeau-speech-convention-liberal_n_3029678.html" target="_blank">titled "Hope and Hard Work," </a>makes no mention of his marijuana policies but does attack the Tory tough-on crime agenda. "The Conservatives have forgotten about the value of service," he says. "The only time they talk about community service these days is when it's punishment for a crime."

  • About a week later, Trudeau <a href="http://www.huffingtonpost.ca/2013/04/14/justin-trudeau-speech-full-liberal-win_n_3082219.html" target="_blank">wins the Liberal leadership</a> with more than 80 per cent of the vote. His victory speech makes no mention of pot.

  • In July of 2013, Trudeau's pot remarks to a group of potential British Columbia voters <a href="http://www.huffingtonpost.ca/2013/07/24/justin-trudeau-marijuana-legal_n_3645624.html" target="_blank">quickly go viral</a>. "I'm actually not in favour of decriminalizing cannabis -- I'm in favour of legalizing it. Tax and regulate. It's one of the only ways to keep it out of the hands of our kids because the current war on drugs, the current model isn't working," <a href="http://www.youtube.com/watch?v=BetOS0y9mNg" target="_blank">he says</a>.

  • In July of 2013, Trudeau tweets that marijuana prohibition is "costly and unsafe."

  • In August of 2013, Trudeau Liberals launch <a href="http://petition.liberal.ca/end-prohibition/?utm_source=liberal&utm_medium=email&utm_content=jb&utm_campaign=marijuana-petition" target="_blank">an online petition</a> calling for an end to marijuana prohibition. "Liberals believe in a smart on crime approach, targeting real criminals instead of ordinary Canadians," it reads.

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