We probably aren't as charitable toward those who have evolved in their beliefs — or even done a complete about-face — as we ought to be. That's likely because we tend to conflate genuine ideological evolution with opportunistic turnaround — with new positions adopted for money, power or influence.

We often assume opportunism when politicians repudiate their own former talking points. That happened when U.S. President Barack Obama changed his position on same-sex marriage, when then-presidential candidate Mitt Romney was found to be rather inconsistent in his views on abortion and when Prime Minister Stephen Harper went from cap-and-trade advocate to adversary.

Perhaps in those and similar cases, the ideological evolutions truly were genuine. Or perhaps these political leaders simply looked deep down in the heart of their polling data to decide what to say, and when. Maybe both.

In any case, the hot new turncoat this season is the prohibitionist politician-turned pot dealer: Men and women who spent their political careers silently upholding — and in some cases advocating for — the criminal imprisonment of cannabis consumers, who are now spending their private careers making money from them.

I am completely opposed to the legalization of marijuana <a href="http://t.co/6xjeipzErR">http://t.co/6xjeipzErR</a> —@JulianFantino

They include former police chief and Conservative cabinet minister Julian Fantino (who once compared legalizing marijuana to legalizing murder); former federal finance minister Joe Oliver (of the Harper tough-on-crime era); and as announced most recently, former prime minister Brian Mulroney, who is joining the board of the New York-based marijuana company Acreage Holdings.

Fantino and Oliver served in the Harper government when it passed Bill C-10, an omnibus bill that, among other things, stipulated a mandatory minimum sentence for those caught growing six or more (up to 200) cannabis plants. Fantino, when he was Veterans Affairs minister and running for re-election, distributed Reefer Madness-eque flyers in his riding warning that "Justin Trudeau will make harmful drugs more accessible in Vaughan." Both Fantino and Oliver are now involved in the medical marijuana business — medical being a distinction that is ostensibly important now, but not back when they were in government.

Canada's Drug Strategy

In many ways, Mulroney was the Ronald Reagan to Canada's very own war on drugs. In the late 1980s, he declared that "drug abuse has become an epidemic that undermines our economic as well as our social fabric," and launched a $210-million program called Canada's Drug Strategy, which was purportedly focused on harm reduction.

But around the same time, his government also introduced Bill C-264, which amended the Criminal Code to prohibit sale of literature or paraphernalia for illicit drug use — punishable by hefty fines and possible prison time — as well as Bill C-61, which expanded police powers to raid property and seize assets of alleged drug traffickers. Then, as now, the overwhelming majority of police-reported drug offences were for marijuana-related activities. In 1990, for example, 63 per cent of drug offences were for simple possession of cannabis.

Mulroney offered the Canadian answer to then-president Ronald Reagan's War on Drugs.

We know that many Canadians' lives were completely derailed — some perhaps ruined — because of decisions made in Parliament. That's not to absolve individuals of personal responsibility, of course, but to highlight the fact that these now outdated laws had years-long effects on regular Canadians, while a few powerful Canadians walked away not only unscathed, but reaping the financial benefits. It was politically expedient to be a prohibitionist then; it's economically expedient — especially for those who can coast off the name-recognition garnered from a career in politics — to take the opposite position now.

Perhaps, as mentioned earlier, these ideological evolutions truly were genuine, and perhaps these former politicians should be commended for at least coming that far. To confess to a genuine about-face in thinking is hard, not only because changing your thinking is hard, but also because the typical response is not "welcome, friend" but "what took you so long, hypocrite?"

But there's an obvious reason why Canadians would assume opportunity, rather than a true change of heart, was at play in the cases of Mulroney, Fantino, Oliver, Herb Dhaliwal, Leona Aglukkaq, Kash Heed, Ernie Eves and other former politicians who belatedly came to realize the relative innocuousness of medical or recreational marijuana.

These aren't average Joes whose views on cannabis have changed; they were and are enormously powerful people who oversaw the arrest, prosecution and punishment of thousands of Canadians who possessed substances about which they have not only changed their views, but which will now be a money-maker for them.

To be perceived as truly genuine, such a dramatic, public about-face should probably come with a good degree of humility. Graciousness. Charity toward those you may have wronged, and also toward those with whom you were previously aligned. And the pursuit of lucrative business deals should probably wait, at the very least, until those affected by your past decisions know if and when they may apply for a pardon.

This column is part of CBC's Opinion section. For more information about this section, please read this editor's blog and our FAQ.