just speculating now: the beloved justice scalia was poisoned, probably by a cabal of anti-originalist legal scholars centered at harvard law school. be this as it may, everyone is pointing out with their sudden generosity that scalia revived fundamental questions about constitutional interpretation. i think he had a pretty primitive theory. also i think most of his opponents have a pretty primitive theory, and a pretty primitive refutation of his theory. so, there are many cases where the original intent of the constitution is, for example, not singular. i will point out that it was a committee production involving an extremely wide range of political and legal positions, enshrining a number of compromises. there is not always or usually a clear or single intent, and what hamilton thought the thing meant and jefferson/madison were probably as different as what cruz thinks it means and sanders. also, even if we had a completely clear intent, the question would certainly remain of what we owe to that intent and why. also, it's not the case that the alternative to originalism is 'anything goes', as scalia himself liked to assert. there are many immediately obvious middle ways through.
however, i understand why scalia wanted to go fundamentalist, because specifically the left actually really doesn't care about the constitution at all, thinks we owe it nothing, and regards it only as an annoying barrier to the state annexing more and more aspects of everyone's lives: i.e. it is a barrier to progress. well, i am definitely enthusiastic about shoring up all barriers to progress thus construed. i think the constitution enshrines a vision of strictly limited governement that is what is distinctive about the american polity, and is also the sort of thing that in a pinch might save you from dying at the hands of your own genocidal megalomaniacal state. it's been an extremely useful hedge against toalitarianism, and if the left really could just ditch it out they'd start a cultural revolution.
also, the anti-originalists often say things like this: it is impossible to know the intent of the framers! what are you going to do, read the mind of people who have been dead for centuries? what a useless, fantastic notion, etc. please. are you telling me, for example, that it is impossible to know anything about the intentions of john milton as you read paradise lost, or david hume as he wrote the treatise of human nature? they both actually kind of told you what their intent was, and a lot of it is pretty darned legible right in the text. we interpret the intent of old-timey authors all the time. it's a difficult matter, and you have to get into the details, and maybe there will always be some lacunae. but really, interpreting the intent of dead people is a perfectly ordinary human activity, and for example literary scholars do it all the time. you could start with careful etymologies: how were the terms 'militia' or 'liberty' or 'speech' used in various sorts of texts of the day, and so forth. please don't tell me that you think such things are a priori impossible.
and then, plus, it's perfectly true, as scalia said, that plenty of people on the left really just want the thing to say whatever they want it to say, and have developed a theory of interpretation that would make that possible. of course, their theory makes all interpretation of any text impossible. i would say in both cases, cutting to the chase, or peeling back the layers of obfuscation, we really have very primitive and ridiculous competing theories of interpretation. i don't know: read gadamer's truth and method or something and get back to me. fuse the horizons, baby.
i would prefer not to focus on intent, which is not the same as meaning. intent could be relevant. but language is public, not in your head. i would prefer to think about the meaning of text in its original context, and it is in that context that whatever intentions were floating about were formed. again, you'd start with the ways particular words were used, not in madison's head, or not only in madison's head, but in the culture, conversation, and written texts of the era. seriously, i could say something i did not intend to say - i often have - but it wouldn't follow that my utterance was meaningless or that it might mean anything at all. we know, in our rough way, how to figure out what people mean from the words they use, and so on, and this is partly a matter of what those words mean in the public language. what they meant in madison's head was fixed by their public uses, though of course the public uses might be multivalent, ambiguous, or obscure, or madison might have had a self-serving or mistaken or pejorative use of some particular word or phrase. that madison was pretty darn clear and competent in the use of language, however.
anyway, yes, pragmatically, i want to be able to appeal to a strong constitution to defend against encroachments on my speech and so forth. i feel that it has kept me out of the re-education camps. overall, it's a pretty useful and good thing, and it has sort of helped fend off authoritarianism - and hence murder, pain, rape, and extreme inequality - though actually it has been chewed up to move in that direction in a pretty consistent arc. if it's got to be at this level, then i guess i'm going with originalism. but really, it can't be at this level; seems like law profs should be able to do better or could think more carefully or devote themselves to something other than mere partisanship.