The ‘Canadian case’ often sits awkwardly in theories of comparative judicial power. In part, this is because of a failure to appreciate the complexities of Canada’s constitutional order, which allows for considerable informal flexibility within formal boundaries. From the perspective of ‘constitutional dialogue’, the typical Canadian case might lead observers to find its system indistinguishable from judicial supremacy. Such an approach would miss, however, the infrequent-but-real opportunities for non-judicial actors to play a role in the development of its constitutional principles. In other words, it is the formal separation of powers — deeply ingrained in Canada's constitutional design — that ultimately determines the course of any constitutional dialogue. One such formal ‘coordinate moment’ recently occurred in Canada with Parliament’s response to the Supreme Court of Canada’s ruling in the assisted suicide case of Carter v. Canada. That case — and the response it generated — demonstrates one ‘feature’ of how Canadian constitutional supremacy is reconciled with an inter-institutional approach that does not privilege the judiciary. As such, and understood in this way, the Canadian case has much to offer other Westminster systems that may be struggling with the role Parliament might play when a written and entrenched constitution is ‘supreme’.