Learning by doing: constitutional imperatives

After reading the first ten judgments of the Supreme Court of Canada’s 2026 term, I had expected this post to be short and observational: as more constitutional imperatives are recognized, they seem to be getting longer, more concrete, and much less elegant.

In R. v. Hussein, 2026 SCC 2, Wagner CJC for the majority recognized three constitutional imperatives which seem to be closely related:

1. “treating Crown-led evidence of an accused’s bad character as presumptively inadmissible” (¶1);
2. “prohibiting the trier of fact from inferring guilt simply because the accused appears to be the “type” of person to commit the crime” (¶1); and
3. “a trial judge’s duty to properly exercise their common law discretion to exclude evidence that would result in an unfair trial for an accused” (¶63).

Whereas the first two imperatives “uphold” the common law principle “that a criminal trial is not a forum to pass judgment on the general character of the accused” (¶1), the third has acquired constitutional status “in light of ss. 7 and 11(d) of the Charter” (¶63).

Leaving aside their function and source for now, they sound much more like the new imperative recognized in Power v. Canada (AG), 2024 SCC 26 – “the constitutional imperative that the government be afforded the autonomy to govern effectively” (¶115) – than the concise, canonical imperatives from earlier cases, such as order, fairness, judicial independence, parliamentary privilege, and the duty to consult.

But why would the Court suddenly grow more verbose and specific? Have the Justices simply plucked the lowest-hanging imperatives and now must stretch their conceptual and compositional muscles to reach less obvious ones? Might they be just as confused as we are about the nature, origins, and meaning of these unusual – yet apparently fundamental – constitutional elements?

Before leaping to a new hypothesis, I remembered Hussein is just one more datapoint and one more opportunity to refine my understanding of its precedents.

In a previous post, I argued the Court minted at least two constitutional imperatives in Power: “the government be afforded the autonomy to govern effectively” and “limited government immunity”. While the majority opinion in that case withheld the label from it, “limited government immunity” nonetheless satisfied the three emergent criteria for a constitutional imperative: 

1. it was required by constitutional principles, including parliamentary sovereignty, the separation of powers, parliamentary privilege, and “the rule of law and constitutionality” (¶¶48-58);
2. it was a legal rule or doctrine, rather than a concept or interpretive lens; and
3. it was bound up with legitimacy.

However, on closer reflection after Hussein, “limited government immunity” may be another expression of the constitutional imperative that “the government be afforded the autonomy to govern effectively”. 

According to the Power majority, “limited government immunity” appears to be required by the same set of constitutional principles as the latter (¶¶1, 48-58, 115). One seems to be the consequence – or requirement – of the other: two sides of the same coin.

So, perhaps the constitutional imperatives from Hussein might also reduce to a more abstract form.

Level of Detail	Power v. Canada (AG)	R. v. Hussein
Specific	the government [must] be afforded the autonomy to govern effectively	treating Crown-led evidence of an accused’s bad character as presumptively inadmissible
		prohibiting the trier of fact from inferring guilt simply because the accused appears to be the “type” of person to commit the crime
		a trial judge’s duty to properly exercise their common law discretion to exclude evidence that would result in an unfair trial for an accused
Abstract	limited government immunity	?????

Hussein itself relied on the majority opinion in R. v. Harrer, [1995] 3 S.C.R. 562 at ¶24, where La Forest J explained:

The effect of s. 11(d), then, is to transform this high duty of the judge at common law to a constitutional imperative.  As I noted in Thomson Newspapers, at p. 563, judges must, as guardians of the Constitution, exercise this discretion where necessary to give effect to the Charter‘s guarantee of a fair trial. In a word, there is no need to resort to s. 24(2), or s. 24(1) for that matter.  In such circumstances, the evidence is excluded to conform to the constitutional mandate guaranteeing a fair trial, i.e., to prevent a trial from being unfair at the outset.

This excerpt confirms the conceptual chemistry: a Charter provision can turn a common law duty into a constitutional imperative, also known as a mandate or requirement. 

Increasingly, constitutional imperatives appear to be the “structural doctrines” identified by the majority in Toronto (City) v. Ontario (Attorney General), 2021 SCC 34 when explaining the second legitimate use of constitutional principles: “unwritten principles can be used to develop structural doctrines unstated in the written Constitution per se, but necessary to the coherence of, and flowing by implication from, its architecture” (¶56). They are legal doctrines that judges can use to resolve certain questions “on which the text of the Constitution is silent”, and they do so by drawing on constitutional principles to maintain and even bolster the legitimacy of the interpretive enterprise. 

Wagner CJC also used Harrer on behalf of the entire Court in R. v. Kinamore, 2025 SCC 19 at ¶75: 

Myths and stereotypes about sexual assault complainants undermine the fairness of a trial by distorting its truth-seeking function (R. v. Mills, 1999 CanLII 637 (SCC), [1999] 3 S.C.R. 668, at para. 119; J.J., at para. 162; Kruk, at para. 43). When relied on by the Crown, myths and stereotypes risk undermining an accused’s right “not to be convicted except on evidence directly relevant to the charge in question” (Corbett, at p. 697). Therefore, trial judges must exclude this evidence as part of the “constitutional imperative” to exclude evidence that would result in an unfair trial for the accused.

In turn, this excerpt confirms that constitutional imperatives can be composed of parts. It identifies one of the constitutional imperatives from ¶1 of Hussein “as part of” the constitutional imperative identified in ¶63 of that judgment (as well as in Harrer and Kinamore). It tells us that constitutional imperatives can be composite; they can have different elements, facets, or parts. 

This observation invites the question: what is the more abstract (or synthetic) expression of this constitutional imperative, which was expressed three different ways in those three cases? 

One more search revealed the answer in R. v. Haevischer, 2023 SCC 11 at ¶56: “In criminal cases, trial fairness is more than a policy goal: it is a constitutional imperative.”

So I could complete the table above, and “trial fairness” could become my gallium or germanium, my Top Quark or Higgs Boson:

	Power v. Canada (AG)	R. v. Hussein
Specific	the government [must] be afforded the autonomy to govern effectively	treating Crown-led evidence of an accused’s bad character as presumptively inadmissible
		prohibiting the trier of fact from inferring guilt simply because the accused appears to be the “type” of person to commit the crime
		a trial judge’s duty to properly exercise their common law discretion to exclude evidence that would result in an unfair trial for an accused
Abstract	limited government immunity	trial fairness

This analysis disproved my initial hypothesis: there is no trend towards longer, less elegant constitutional imperatives. 

Rather, further reflection and research revealed:

1. trial fairness has entered the pantheon of constitutional imperatives;
2. “limited government immunity” is better understood as a more abstract expression of the constitutional imperative that “the government be afforded the autonomy to govern effectively”, rather than as a separate constitutional imperative;
3. constitutional imperatives are increasingly likely to be the “structural doctrines” that constitutional principles can elucidate from our basic constitutional architecture; and
4. constitutional imperatives can be composed of parts, which can be articulated at different levels of abstraction.