Justin Trudeau campaigned on a promise to restore cabinet government; and, after a decade of hyper-control by Stephen Harper, Canadians welcomed the idea. But is it really possible to turn back the clock? That may be the most important question facing the new prime minister.A brief historical overview will help us put things in context before drawing some conclusions.The 1960s were a high-water mark for cabinet government in Canada. When forming policy, Lester B Pearson's ministers consulted with the caucus, party officials, riding associations and people in their communities, as well as relying on the expertise of their public servants. Ideas were presented to cabinet, where they were vetted and decided on in a collegial way.Things started to go awry in the early 1970s. Although many factors were at play, the rise of public opinion research and marketing (POR) must be singled out as the principal driver.As Susan Delacourt has so ably shown in Shopping for Votes, strategists may have thought these tools would improve the existing policy process but, instead, POR sent politics spinning off in a whole new direction.By the end of the '70s, a good pollster could find out more about an issue in 48 hours than MPs could learn in two months. Throughout the 1980s pollsters honed their skills, as government leaders around the world flocked to them for policy advice.By the end of the decade, polling was king. Prime Minister Brian Mulroney's pollster, Allan Gregg, was a case in point. He had become a Canadian media celebrity and was as influential on policy matters as most senior ministers.But success had a dark side. As the pollsters' star rose, the influence of caucus, cabinet and the public service faded. By the late 1990s, Donald Savoie, a leading authority on the subject, had declared that cabinet government was effectively dead in Canada.Policymaking, he said, was now the privilege of the prime minister, a handful of advisors in the PMO and a few select ministers. Cabinet had been reduced to a focus group.Actually, things were even worse than he thought. While POR may have been an effective way to identify policies, the government still had to “sell” the ideas to the public. This, in turn, called for a marketing strategy.Westminster governments like the UK, Australia and Canada turned to the old party networks for help. But rather than consulting caucus on issues, MPs were called on to serve as messengers—or salespersons—for their governments.The media was also affected. The more government focused on trying to “sell” its ideas, the more consistency became the gold standard for their validity. Ministers who changed a policy proposal were accused of “backtracking” or “flip-flopping,” the sure sign of a problem. Catching the minister off-message became a media preoccupation.Strategists, unsurprisingly, responded with yet more message control.In the early 2000s, the emergence of social media and the 24-hour news cycle deepened these concerns, leading to increasingly rigorous forms of discipline to keep caucus members and party spokespersons on message.The Harper majority of 2011 was the final act, and the logical conclusion, of this 40-year drama. Under this regime any lingering hope of a return to cabinet government vanished.No one doubted that policy was made in the PMO or that once a decision was taken the government would have no interest in trying to improve it. Communications strategies were designed to minimize debate, not foster it—which brings us to the present.Election 42 appears to have been a turning point. The spectacle of MPs like Paul Calandra and Pierre Poilievre rattling off their talking points was not just insulting to Canadians' intelligence, but stark evidence of the PMO's iron grip on the policy process and its contempt for democracy.Apparently, Canadians have had enough. Trudeau's promise to revive cabinet government was a clear rejection of this whole trend in politics and people embraced it. The question now is whether he can make it work.Back in the 1960s, cabinet government succeeded because ministers weren't just selling an idea. They were trying to develop one. Public input and feedback were needed to get the policy right and the process was there to help them.As a result, everyone was more open to seeing ideas change and evolve as the process unfolded. Decision-making came at the end of the process, not the beginning.If Trudeau wants to revive cabinet government, this is the key to success. Not only must the PMO be willing to relax the message control and allow a more open process to work. The policy process must be redesigned to produce policies, rather than to sell them.There is nothing starry-eyed or utopian about this. Cabinet government worked before and it can work again. First and foremost, it is a question of political will. However, the context has changed and Trudeau will need to address this.For one thing, the policy arena is far more crowded than in Pearson's time. Thousands of private and civil society organizations are now active, both as advocates and experts.The public service has been marginalized and must be re-energized and re-engaged.Very sophisticated data and information systems have emerged that must be integrated into policymaking.Finally, over the last two decades, an impressive range of social media tools have emerged. Cabinet government must harness and use them.So where do we start? In Pearson's day, cabinet government relied on the party's network of relationships to support discussion and debate. This is no longer adequate.The government needs new engagement infrastructure—online as well as face-to-face—and a new generation of dialogue processes for the 21st century. These processes must make room for real give and take. Ideas must be allowed to evolve and change as the process unfolds.At the same time, policymaking cannot be a free-for-all. It needs structure and leadership. Ministers have lots to learn and they can start by experimenting with policy processes that encourage real dialogue, while looking for ways to build consensus.Nor is this wishful thinking. Models for such processes exist and lots of work is being done to test and refine them, both in Canada and abroad.MPs could also play a key role here through re-energized committees and/or special committees to engage stakeholders and citizens on key issues.In the end, the Golden Rule for cabinet government is simply this: decision-making comes at the end of the process, not the beginning. The way to make cabinet government work, whether in the last century or this one, is to embrace this principle and let it guide the policy process.The prime minister has the right idea. Now he just needs to act on it.Dr. Don Lenihan is Senior Associate, Policy and Engagement, at Canada 2020, Canada's leading, independent progressive think-tank. Don is an internationally recognized expert on democracy and Open Government. He is currently the Government of Ontario's principal advisor on its Open Dialogue Initiative. The views expressed here are those of the columnist alone. Don can be reached at:[email protected] or follow him on Twitter at: @DonLenihan