The key to understanding Stephen Harper's federalism is heroin.

Got your attention? Good. The word "federalism" tends to put people to sleep, but this is important stuff so I'll try to sex it up. Hence, heroin.

There's lots of it in Vancouver's benighted downtown eastside, as there has been for decades. Law enforcement and social services tried everything they could think of to get rid of the drugs and the crime and the social blights. But things only got worse.

In the mid-1990s, HIV and hep C were epidemic and overdoses soared. In 1993 alone, 200 people died.

In desperation, city officials turned to an idea tried with considerable success in Europe. Insite opened its doors in 2003.

Insite was an experiment. Drug users would be allowed to enter the premises with illicit drugs they had bought on the street - usually heroin or cocaine - and inject themselves in a clean place supervised by nurses. It was hoped that overdose deaths would decline, along with transmission of HIV and hepatitis C. And social workers would be better able to connect with marginalized addicts and steer them to detox and treatment.

Which is exactly what happened. A stack of studies published in the most prestigious peer-reviewed medical journals in the world confirmed that Insite saved lives.

Stephen Harper wasn't impressed, apparently. His government spent years trying to shut the facility down.

Under the Constitution, health and social services are provincial jurisdictions and the government of British Columbia supported Insite. So did the city of Vancouver. And the Vancouver police. And Vancouver social services. In fact, Insite had overwhelming local support.

But possession of heroin or cocaine is a crime, and criminal law is the jurisdiction of the federal government. Thus, for Insite to operate, it had to have a special exemption from the federal government. Federal law said such exemptions could be given for medical or scientific purposes. But the feds refused to renew it. No matter how clearly Insite fit the expectations of the law. No matter how the evidence in its favour piled up. The feds refused. So it would have to shut down.

Inevitably, the dispute went to the courts. Last September, the Supreme Court of Canada delivered its decision.

On the question of constitutional authority, the federal government won. The province does not have exclusive jurisdiction, the Supreme Court ruled, so Insite does require a federal exemption.

However, the Supreme Court further concluded the federal government hadn't exercised its discretionary power properly. In blunt language, the court said the federal government had acted arbitrarily and grossly disproportionately. And since lives were at stake, that violated the Charter of Rights.

It was a crushing defeat. But that's not the point here. More important for present purposes is what this episode says about Stephen Harper's approach to federalism.

Harper has always been an ardent and vocal decentralist, decrying federal government intrusiveness and demanding maximum latitude for provincial decision-making. The arguments he has used are classics. Straight from Poli Sci 101.

Which is what makes the Insite case so illuminating.

Insite could be the poster child for decentralization. It used local knowledge. It was supported locally. It was born of a local political culture that was very different from political culture elsewhere. And it was an experiment whose results could be studied by other jurisdictions. That ticks most of the decentralist boxes (which I outlined in my last column). And while it's true that Insite triggers the federal government's criminal law power, mostly it falls under health and social services - two areas the Constitution deems provincial jurisdiction.

If ever there was a case where a decentralist would say the federal government should butt out and let the province do its own thing, this was it.

But Stephen Harper refused to butt out.

Now recall the prime minister's plan for a national securities regulator. Provinces had been regulating securities since Confederation so it was clearly intruding on provincial jurisdiction. The federal government lamely argued that a changed economic environment somehow changed the jurisdictional question but in a December decision the Supreme Court unanimously rejected that. Harper's plan was an unconstitutional intrusion on provincial jurisdiction.

Further, consider how Harper has handled the federalism aspect of his criminal law policies.

Yes, the Constitution assigns the writing of criminal law to the federal government. But the administration of justice is a provincial mandate. In effect, the Constitution makes criminal justice a split jurisdiction, and that is how federal governments have always treated it - consulting closely with the provinces and not imposing laws that would have big impacts on the provinces if the provinces were opposed. But not this prime minister. He hasn't consulted. And when some of the provinces objected to the major costs they will bear thanks to the feds' omnibus crime bill, Harper told them to lump it.

Back in 2006, a few months after taking power, Harper declared "the time has come to establish a new relationship with the provinces - a relationship that is open, honest, respectful." At the time, this was taken as a signal that Harper's federal government would back off and the decentralization he had long advocated would unfold.

Many pundits seem to think that's what happened, and continues to. Look at the health deal, they say. It pulls the feds back from direct involvement in health policy, giving provinces greater latitude to decide policy. Classic decentralization.

Indeed. But look at the rest of Stephen Harper's record.

What I see isn't a prime minister pursuing decentralization as a philosophy of governance, or adhering to the demarcations of the Constitution. I see a prime minister who decentralizes what he doesn't care to control and centralizes what he does.

I see a prime minister who is pursuing, in this as in all things, his own power.