Brad DeLong lists 10 constitutional revolutions in American history. I'd quibble with some of his inclusions (only an economist would think the Bork-Posner inspired change in interpretation of competition law equals the Warren Court or the "Switch in time that saved nine"), at least one exclusion (the post-civil war cases that gutted the newly enacted Fourteenth Amendment other than the due process clause) and a bunch of the normative valuations (DeLong tries to persuade us that reading the "interstate commerce clause" as if it is a grant of full sovereign power over everything is being faithful to the text).
But, more importantly, I read it is as a challenge. What are the "revolutions" in Canadian constitutional law -- in addition to the formal ones on July 1, 1867 and April 2, 1982? Can I come up with a list? (I am going to avoid normativity here. Some of these revolutions are approved of by the Pithlord; others not so much.)
1881 Parsons gave the provinces something to do. Reasoning that the grant of power over "Property and Civil Rights" was intended to give Quebec a different system of private law, and that regulating an industry like insurance is really about modifying the common law or civil law of contract, the JCPC cut back on the federal government's "Trade and Commerce" power. Good move, if you ask me.
Late nineteenth century -- culminating in The Liquidators of the Maritime Bank of Canada v. The Receiver-General of New Brunswick,  A.C. 437 -- the Privy Council confirms Oliver Mowat's vision of a genuine federation with co-equal levels of government at the expense of John A. Macdonald's imperial vision.
1945-50. The spending power revolution, and deposition of the Privy Council in the Immediate post-WWII period. Basically, the Anglo governments just ignored the New Deal cases saying that the federal government cannot spend unless it legislates, and therefore cannot spend in areas of provincial jurisdiction. Tax-and-spend with conditionality basically permits the feds to enter any area of policy, although sometimes with an inefficient policy instrument.
1985 Court imports "substantive due process" into Canada under section 7 against the explicit wishes of all the politicians involved in negotiating the Charter three or four years earlier. Logically, no limit to judicial power. The consummation of the revolution doesn't occur until 2005's Chaoulli decision, when the Court decides it would like to dictate health policy.
1989 Court decides that "every individual has the right to equal protection and equal benefit of the law" means only an individual in a list of protected groups we make up has equality rights, and these rights can mysteriously be invoked even where there is equal treatment under the law. In Law, the Court made equality rights even more subjective by saying they could only be invoked when judges think "human dignity" is involved. This means nothing other than "when we say so."
1990 Court invokes dubious regulation/extinction distinction to overturn compromise in aboriginal rights provision of 1982 Constitution. In 1981, Lougheed (and a stunned Bennett) agreed to section 35 as a standstill clause -- governments would not be permitted to take away aboriginal rights they had already recognized. That was the purpose of adding the word "existing". Sparrow and Delgamuukw took away any meaning to that word. There was a poision pill for aboriginals too, though, since new restrictions on aboriginal rights became acceptable provided the courts thought they were for a good cause.
1997 On its own motion, Court decides -- contrary to 400 years of precedent -- that it can strike down duly-enacted laws without reference to written constitutional provisions.
Also in 1997, the Court gave the federal government virtually unlimited ability to regulate under the criminal law power. Now, the feds aren't even limited in their policy instrument.
That makes seven. I am not counting a number of failed revolutions -- the attempt by part of the Court between the thirties and fifties to create an implied bill of rights, or Laskin's attempt to formally overturn the Privy Council's subsidiarity-based federalism jurisprudence.