Larry Solum has posted a lengthy paper defending "semantic originalism" as the way to interpret (but not construct!) a written constitution.
The upshot is that originalism is right, but doesn't matter nearly as much as everyone used to think.
As Solum tells it, semantic originalism involves four claims:
1. The fixation thesis. The semantic meaning of the constitution (what is says, not what it does) is fixed at the moment it is adopted. Linguistic change since 1867 does not change what the BNA Act means.
Importantly, this does not imply that change other than in the meanings of words since 1867 will make no difference in how constitutional cases will be decided.
2. The clause meaning thesis. What matters is not what the authors of the constitutional text intended, but what a competent reader at the time would understand. Competent readers might be the general public, politicians, lawyers or possibly different groups for different clauses.
3. The contribution thesis. The meaning of the Constitution has some effect on the law of the constitution. Not necessarily a big one, though.
4. The fidelity thesis. We ought to respect the law, including constitutional law, unless there is a good reason not to.
Let's take the facts of Edwards v. Canada,  A.C. 124 (P.C.) to see how this plays out. The British North America Act, written in 1867, permitted the Governor General to name "qualified persons" to the Senate. In 1867, women, including peeresses in their own right, were under a legal disability from voting in Parliament.
The Privy Council decided that women could be Senators. It could have done so by referring to the meaning of "person" in 1930, by referring to a secret intention of John A. MacDonald to have women as senators, by deciding that the constitutional law had changed in the interim or by deciding that excluding women from the Senate was too unjust a law to obey. If you attended U. of T. law school, you would be forgiven to think that that is what they did, although of course, they didn't.
The Constitution makers in 1867 presumably thought this disability would continue. However, as the Privy Council decided, the term "person", if unqualified, included women. Even if it was taken more narrowly to include only individuals with legal capacity, by 1930, married women had such capacity and therefore had become "persons," although they would not have been sixty years earlier. The Privy Council was aware that if the BNA Act had used the phrase "qualified men", then it would clearly be saying that women could not be Senators, regardless of whether that was a just result.
Solum distinguishes between "constituional interpretation" (which derives the meaning of the text) and "constitutional construction" (which is what judges do when the meaning runs out. Most cases are decided at the construction stage.
Solum says that "constitutional construction" involves vagueness and pragmatics (meaning of utterance, rather than utterance-type). Here I would tend to disagree. Pragmatics about the constitutional utterance itself go to interpretation. We know that the "United States" means the United States of America because of whose constitution it is, just as we know that "I did it" refers to the Pithlord because of who said those words.
Where vagueness goes is more of a matter of choice, but vaguness definitely does not exhaust the post-interpretive issues of constitutional litigation. The issue in constitutional construction is not usually what side of a vague line a statute is on, but whether certain social/moral facts are true. Whether lethal injection is "cruel and unusual" turns on the social fact of whether there is a less painful method to kill people and the moral fact of whether killing people that way is cruel. Whether the Ocean Dumping Control Act interferes with property and civil rights within the province depends on whether ocean dumping is a trans-border externality that requires a regulatory scheme to address. Whether the pre-1988 abortion law is contrary to the principles of fundamental justice depends on whether the tribunals it set up were unbiased and reasonably speedy.
Solum's form of originalism may not matter very much north of the border. In the Candian case, since our most controversial constitutional provisions are just over 25 years old, there has not been any linguistic change for the fixation thesis to operate on. Almost none of the Charter decisions turn on the semantic meanings of the words.
The exception may be those provisions where the words arguably had a "term of art" meaning in 1982. The critical example was "principles of fundamental justice," which had acquired among lawyers a purely procedural meaning as a result of previous Supreme Court decisions. Unfortunately, in 1985 when this provision was considered, we did not have a sophisticated originalism up here, and the Canadian courts would have been naturally resistant to Reaganite terminology.