Until recently, Trudeau said he backed decriminalization, but expressed skepticism about full-blown legalization, even though his party adopted the position in January 2012.
But while travelling in B.C. this week, as part of a cross-country summer motorhome trip, Trudeau announced first in the Okanagan city of Kelowna Tuesday and then in Vancouver Thursday that he backed legalization.
"I did a lot of listening, a lot of reading and a lot of paying attention to the very serious studies that have come out, and I realized that going the road of legalization is actually a responsible thing to look at and to do," he said during a stop at Vancouver's English Bay.
“Marijuana is not a health food supplement. It’s not great for you, but it’s certainly, as many studies have shown, not worse for you than cigarettes or alcohol."
The comments come at a key moment of the debate in B.C.
Pot activist Dana Larsen and his organization Sensible BC have been given a green light to begin collecting names for a petition in September to decriminalize the drug. The drive wants to see police prevented from enforcing simple possession laws.
Jodie Emery, the wife of Marc Emery, Canada's so-called Prince of Pot currently imprisoned in the U.S., also announced earlier this month that her husband could soon be transferred to a Canadian prison.
The Conservative government, though, questioned whether Trudeau has the judgement to be the prime minister.
"These drugs are illegal because of the harmful effect they have on users and on society," the party wrote on its website. "We will continue protecting the interests of families across this country.
"Our government has no interest in seeing marijuana legalized or made more easily available to youth."
To support their argument, the Conservatives cited statements from the Canadian Police Association, a former RCMP commissioner, the Drug Prevention Network of Canada, and a criminologist from the University of the Fraser Valley.
Meantime, pot activists applauded Trudeau's new position.
"Having a candidate for prime minister say he wants to legalize marijuana, it just continues the mainstreaming of this perception, of this idea," said Larsen.
He said there was a time when only former politicians talked about legalization, but then current politicians began to speak out, too.
In fact, B.C.'s former Liberal attorney general Geoff Plant and former NDP premier Ujjal Dosanjh have called for the legalization and regulation of marijuana. Their group, the Stop The Violence B.C. Coalition, has pointed to opinion polls that suggest a majority of British Columbians agree with them.
"This just shows how this issue has moved perhaps from what might have been seen as an unpopular fringe issue 10 or 20 or 30 years ago into something where the vast majority of Canadians support this and major politicians feel comfortable expressing this view," said Larsen.
Jodie Emery said it was great to hear Trudeau has joined the pro-legalization side of the debate.
"I don't know if this impacts Marc's situation, but it's good to know that when Marc does return home we'll have a potential prime minister who favours reforming our marijuana laws," she said.
"I think we'll be happy to support Justin Trudeau and his run to become prime minister if he's going to really be serious about making sure prohibition is addressed and serious action is taken."
British Columbia's Liberals have stayed out of the debate, arguing drug laws are federal. In fact, during the campaign leading up to the May provincial election, Premier Christy Clark ridiculed her NDP opponent for even taking a position on the issue.
The Sensible BC campaign was given two months to sign up canvassers and prepare to start collecting signatures Sept. 9.
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