Justin Trudeau's promise of legal and regulated marijuana has crashed into Justin Trudeau's promise of an independent Senate.

And so, this is your new Senate on weed: 46 amendments and, appropriately enough, some second thoughts about a potential threat to sobriety.

One of those changes merely adds a comma, and many of the others are technical in nature, but 46 amendments for the House of Commons to consider is still rather more than one reasonably might have expected from the Senate in recent years. Eight of the amendments were sponsored by Conservative senators.

All that after the Senate's desire to review the bill forced the government to push back its timeline.

Bill C-45 — which passed, amended, by a Senate vote of 56 to 30 with one abstention last night — is the ninth government bill to be sent back to the House since Trudeau began filling the upper chamber with independent senators. Between 2011 and 2015, the Conservative-dominated Senate sent back just one bill.

Indeed, if nothing else, Trudeau's reforms have awakened Conservative senators to the value of challenging the government of the day.

Emails released during the Duffy affair, for instance, showed that Conservative Senator Carolyn Stewart Olsen once told Stephen Harper's chief of staff that she was "always ready to do exactly what is asked." On Wednesday, Stewart Olsen suggested a group of Indigenous senators had capitulated when they declined to insist on a series of amendments to the marijuana bill.

Conservative Sen, Carolyn Stewart Olsen once told Stephen Harper's chief of staff that she was "always ready to do exactly what is asked." Like a lot of other Conservative caucus members, she's embraced the idea of pushing back against the government of the day. (Fred Chartrand/Canadian Press)

But with all due respect to sober second thought, the nature of the Senate's existence is rather secondary here to the seismic change in drug policy now at hand.

On that note, the waning hours of debate in the Red Chamber offered a chance both to underline the case for change and the potential for trouble.

Are we ready for legal weed?

Leading the last day of debate, Conservative Senator Larry Smith offered much of the latter. He was concerned, he said, that C-45 would impose greater risks on young people and greater challenges on law enforcement. There would be new impacts on job performance and safety, wide-ranging implications for the health care system and new problems at the border.

The government, he argued, had not done enough to educate the public about the risks of legal marijuana, or to prepare linguistically and culturally appropriate educational materials for Indigenous communities. He also had concerns about the need to respect provincial jurisdiction.

Claude Carignan, another Conservative senator, said he worried about the implications for international treaties to which Canada is a signatory. Judith Seidman said the passage of C-45 would lead to an increase in use among adults and she said the bill did not go far enough in regulating the advertising of marijuana products.

Some senators suggested that more time and more work would be needed before going forward.

It's possible that more time would have resolved some future issue or another. It's also possible that no amount of time would have resolved Conservative concerns about legalizing and regulating the recreational use of marijuana.

But the mere fact that Conservative senators are around to voice such dissent — calmly and without yelling, in the traditional manner of the un-televised Senate — is at least a reminder that ideological diversity in the upper chamber is at least as valuable as independence.

'The choice is quite simple'

Granted, no one seems to think this is going to go perfectly smoothly. Facing the Conservative senators opposite, Independent Senator Frances Lankin openly acknowledged that there would be problems. But she was comfortable moving forward and scornful of the status quo.

"The choice in front of us today is quite simple," said Independent Senator Andre Pratte, the former journalist and author. "Either we believe that the current system is working ... Or we think that a new approach is needed."

Pratte does not believe the current system is working.

Independent Senator Andre Pratte says the choice on cannabis is simple: between a system that is not working and a "new approach." (Adrian Wyld/Canadian Press)

"Thirty-two per cent. That is the percentage of Canadians aged 20 to 24 who have used cannabis in the last three months, according to the Statistics Canada survey published last April," he said. "This, after a century of prohibition and hundreds of thousands of criminal charges.

"In my view, this puts to rest any remaining debate on the effectiveness of prohibition."

A new approach — a "pragmatic" one — would allow for a frank and mature discussion about marijuana, Pratte said, adding he trusts Canadians to make the right choices.

Liberal Senator Art Eggleton cited a number, too — 18,000, apparently the number of Canadians charged with possession of marijuana. And criminalization, he said, disproportionately punished racialized, Indigenous and low-income Canadians.

'Social order did not unravel'

Eggleton, the former cabinet minister and mayor of Toronto, offered a bit of history. Nearly a century ago, the government of Ontario moved to repeal the province's prohibition on alcohol. The premier at the time was a Progressive Conservative. And the editorial board of the Toronto Star was aghast. Senators chuckled as Eggleton quoted the Star's report of "increased drunkeness" in Winnipeg, Calgary and Edmonton.

And yet, Eggleton noted, "social order in Ontario did not unravel when prohibition was overturned."

"That was later on," quipped Liberal Senator Terry Mercer, seated beside him.

"It's happening today," Eggleton shot back, perhaps in reference to the Ontario election.

In fact, Eggleton continued, in the current Ontario campaign, there was a promise to make alcohol more widely available via corner stores.

He acknowledged that there are still harms associated with alcohol. But the current approach to marijuana, he argued, is broken.

Here, ultimately, is the best hope both for marijuana policy reform in Canada and the independent Senate — that someday, neither will be regarded as a novelty, but as simple facts of life.

Granted, it might be a while yet. One hundred and fifty years after the Senate was legalized, there are still many who don't consider it an acceptable activity.