Grassroots Liberals know what the party needs to stand for in the next election. They made it clear to Justin Trudeau and his government this weekend that they expect the party to continue to push for progressive change, even if it runs counter to the prime minister's own position, and even if it requires more spending than a government wrestling with deficits can afford.

The 15 policy resolutions adopted Saturday at the Liberal Party's policy convention in Halifax aren't binding — they don't have to be part of the 2019 campaign platform. But to ignore them will be difficult, especially when the Liberals are making a concerted pitch for support from young people and progressive voters.

The party voted to decriminalize the possession of small amounts of so-called hard drugs as a way to encourage people to seek help for addictions and to help reduce the epidemic of overdose deaths.

They voted for the Liberals to bring in a national drug plan, to implement a guaranteed basic income, to include mental health coverage in medicare and to come up with a strategy to protect employees' pensions when their employer goes bankrupt.

Every one of those resolutions would be right at home at an NDP policy convention. That Liberal supporters see them as priorities is yet another indication that they believe moving to the political left, to an unabashedly progressive agenda, is the clearest path to re-election next year.

But they all come with a cost and some risk to the government.

Start with the resolution, sponsored by the Liberal caucus, to decriminalize the possession of small amounts of drugs like heroin. It received strong support from young Liberal members who made up close to a third of the 3,000 party supporters at the convention.

Trudeau has indicated he's not prepared to go that far when the government is still trying to push through its bill to legalize marijuana possession in the face of stiff opposition from Conservatives in the Senate, and might still have trouble getting law in place this summer.

The prime minister goes after the Conservative Party, cites government record of change in remarks to delegates in Halifax. 28:38

"On that particular item, it's not part of our plans," Trudeau told reporters covering the convention.

In fact, Trudeau made no mention in his speech to any of the resolutions that had been debated here in Halifax even as he insisted Liberals "are and will continue to be a progressive party."

Even so, he and the rest of his team seem to be on a different path than the grassroots.

The resolution to decriminalize simple possession of all drugs, controversial as it might seem, won a ringing endorsement from Liberal supporters. When the voting was done Saturday, it garnered the third most votes.

The top priority for the Liberals' supporters is the call for universal coverage of prescription drugs. Union members on panels and in the audience spoke forcefully in favour of pharmacare. So did Edmonton Centre MP Randy Boissonnault, noting it was included in Liberal platforms going back two decades.

"It's time," he says.

"Change is the new normal. Young people aren't prepared to wait," he says. "They want to see government move. Votes are fluid. It's our job to tap into what voters want."

Growing to-do list for Liberals

But is it affordable? The parliamentary budget officer says individual Canadians would save billions. That's a good selling point.

On the other side of the ledger it would mean $7 billion more each year in federal spending, a confusing signal after the prime minister told a veteran at one of his town halls just two months ago that some veterans want "more than the government can give right now."

The drug plan resolution most underscores the challenge Liberals face heading into next year's federal election. The Real Change agenda took the Liberals from a third place party in the House of Commons to power. Staying in power requires a more delicate balance of defending their record, while continuing to engage voters who want a continued focus on social activism.

The party's leadership, from Trudeau on down, remains cautious.

They were far more intent on rallying the troops around the list of completed items from the last election: the Canada Child Benefit, the middle class tax cut and the increased benefits under the Canada Pension Plan.

And the to-do list: legalizing marijuana, infrastructure spending and climate change.

"There has been change," says new Liberal Party president Suzanne Cowan, "but that work isn't finished and we need a second mandate to ensure that the things we haven't yet implemented stick."

This week, The House is at the Liberal policy convention in Halifax. Chris Hall talks to participants, MPs, and the new party president about the challenges the Liberals are facing, and the new policies needed to win in 2019. We also ask Barack Obama’s former chief strategy David Axelrod if Justin Trudeau’s “Sunny Ways” pitch will be enough to secure a second win or if he’ll need a new approach and new policies now that the political honeymoon is over. 48:30

Elections 'are about choices'

These things all make the 2019 platform much harder to draft than the last one and make finding the balance between progressive policies and the quest for re-election more difficult.

David Axelrod served as Barack Obama's chief political strategist in the 2008 and 2012 U.S. presidential campaigns. He knows a thing or two about change, and the importance of not straying too far off your message that boosting the middle class remains your mandate.

"The important thing for the Liberal Party is to make clear all the changes they've already implemented," Axelrod said in an interview on CBC Radio's The House. "Elections are not referenda. They are about choices. And it's important to make sure that people know what those choices are."

In the end, the party's leadership chose to focus their efforts at this convention not on policy, but on reminding Liberals, over and over again, that last election's third to first turnaround came out of hard work, raising more money than their opponents and knocking on more doors.

"We have every right to be proud of our accomplishments," Trudeau told the convention in his keynote address. "But it didn't happen by accident and it won't continue without effort."

Other cabinet ministers stressed the importance of remaining united despite the pressures of governing and the disappointments that arise when the aspirational collides with reality.

That was the reason Jim Carr, Catherine McKenna and Dominic LeBlanc made a concerted pitch on the importance of getting the Trans-Mountain pipeline expansion built, acknowledging that the issue is dividing the country and insisting it is part of getting Alberta to put a price on carbon.

"That is why I need you to stand up and support what we are doing to take action on climate change and also support projects that make sense in getting resources to market," McKenna said.

Those cabinet ministers might just want to listen to what's coming back from the grassroots: stand up for a progressive agenda, stand up for real change.