To state the obvious, Conservative MP Maxime Bernier's attempts to irrupt into the liberal orthodoxy of identity politics is a bit rich.

Bernier is, after all, an MP from Quebec, where most people regard their language and culture as something ennobling and worthy of special status and protection, which is the original and biggest identity politics issue Canada has faced. It in fact nearly broke up the country.

That said, Bernier's contention — that identity politics promotes an endless splintering of the polity into ever-narrower shards of cohorts, all of whom believe their ethnicity or religious beliefs or sexuality merit special consideration — is worth discussing. Dismissing Bernier as a nativist, or white nationalist, or simply racist is just more of the reflexive, ad hominem groupthink that's currently so fashionable.

5/ Trudeau’s extreme multiculturalism and cult of diversity will divide us into little tribes that have less and less in common, apart from their dependence on government in Ottawa. These tribes become political clienteles to be bought with taxpayers $ and special privileges. —@MaximeBernier

In any case, Bernier's is hardly a new argument. Todd Gitlin, a respected American public intellectual on the political left, made more or less the same case in the early '90s, complaining that his treasured Rainbow Coalition of the '60s and '70s had shattered, as its constituent groups broke away, intent on separating themselves and promoting their concerns above others. Gitlin argued that power lies in unity and collective will, and that the loss of a collective voice is a path to irrelevance. In retrospect, he had a point.

Maïr Verthuy, a prominent Quebec feminist and first principal of the Simone de Beauvoir Institute at Concordia University, once told me she despaired, watching young feminists subdivide into smaller, insular, competing factions along lines of race and sexuality, which she believed detracted from pursuing the broader struggle for women's equality. Verthuy wanted unity. Effectively, she was saying that unity, rather than diversity, is strength.

Diversity as an end

Our current prime minister famously takes another view. Diversity, to him, is a supreme value; an end in itself.

On the day he swore in his first cabinet, three years ago, he stood before the cameras and told Canadians that the "diversity that makes this country so strong is a diversity of views that will carry us forward." He's been repeating that sort of vacuous tautology ever since. It's his favourite theme.

And, clearly, some of the diversity-and-inclusion agenda is overdue. Those belonging to minority groups have been marginalized, and treated terribly, and that requires redress.

But in Prime Minister Justin Trudeau's mouth, diversity also has obvious subtexts: that whites, especially white males, advance by dint of racial privilege, that merit is utterly relative and that anyone who questions diversity's ever-expanding demands for accommodation — for neologistic pronouns and euphemisms, for tight controls on speech and for recognition that ethnicity or sexuality perforce bestows some sort of unique merit — must be a kind of angry white revanchist, sulking about the disappearance of unmerited privilege, desiring above all a return to the days when minorities and women and non-heterosexuals knew their place.

And while that thinking surely exists — look no further than Trump Nation — Trudeau's full embrace of identity politics probably annoys many Canadians of good will.

It is the Liberal way: if you don't agree with us, we'll smile and explain our policies more slowly. (CBC)

There are people who believe, despite Trudeau's public declarations to the contrary, that there are core Canadian values worth preserving, and a core Canadian identity. Not necessarily the Judeo-Christian one I was taught in school, but also not one that can comfortably co-exist with some of the intolerant, deeply sexist cultural attitudes arriving with some in the legions of immigrants we welcome every year.

I don't know if the woman at the political rally in Quebec on Thursday — the one who shouted questions at him about the costs of accepting "illegal immigrants" — is a person of good will, but she surely did not deserve the brusque bullying treatment she received from the prime minister. She loudly criticized Trudeau at the rally, as is her right, for what she considers his indulgent attitude toward the spike in undocumented people fleeing President Donald Trump's America by simply walking across the border into Canada, overwhelming social service providers in Quebec and Ontario.

A lot of Canadians, no doubt, have concerns about the issue that woman raised, whatever her motivation. A reasonable case can be made that Canada's immigration policies are welcoming and generous, far more so than America's, and should not be ignored. Rather than engage with her, though, Trudeau condescendingly dismissed her as a racist.

It is the Liberal way. If you don't agree with us, we'll smile and explain our policies more slowly, and if after that you still disagree, well, you're a climate change denier, or a racist, or an ideologue not worth the effort of engagement.

So, then, Bernier and his tweets about overdoing diversity. He's a politician who wants to lead his party, and it's easy enough to write him off as an opportunist who's grabbing for a wedge issue.

But it's at least worth having a discussion about his notion that by retreating into ever smaller tribes and inward-facing cohorts, Canada is on its way to standing collectively for nothing at all.

Personally, I'm deeply suspicious of phrases like "common values," or even "patriotism." I dislike nationalism of any sort, and I regard Canada as a convenient modus vivendi in which I am content to participate. I distrust loud declamations about how we live in the best country in the world, etc.

But a common identity can be unifying, even if it rests on foundational myths, as most patriotism does. And unity works.

Say what you like about the Americans, but they've done a remarkable job of creating common identity, despite their insane political polarization. Within one generation, or even earlier, immigrants tend to identify first and foremost as Americans, and only secondarily as whatever their ancestry might be. No other nation has accomplished that, and it is undeniably useful; it creates impermeable unity in crisis.

If that is what Bernier wants for Canada, well, fine, let's talk about that.

He is making his case politely and without insult to any minority group. Shouting him out of the public square only guarantees that the herd of independent thinkers will continue to dispense moral dictation, unbothered.

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