Awesome article, orda. Couldn't agree more. I've argued this endlessly, as you know. It's not that the US Constitution is a sorry document. But it's an eighteenth century one that makes change difficult. So employing it in the twenty first century invites issues.
At some point, the world moves on a ways. And an ancient document gathers wrinkles and looks like it may be due for retirement.
As regards Scalia, he is dodging the issue by recourse to a different one. The obvious response: are new rights feasibly protectable within the US system? Of course they are. So saying that such rights exist on paper but aren't enforced elsewhere is a diversionary tactic and it is irrelevant to the debate.