rwc, I recommend that you read Lawrence v. Texas, or if time is short at least check out Scalia's dissent (which is pretty funny btw) to see what all the hubbub is about. It may not be clear if you just read this article out of context, but the position that Ginsberg is defending is essentially this: judges should look to foreign legislatures to see what the US Constitution means, even if that foreign position is 180 degrees from what the Constitution meant when it was written.
Spartacus, I concede every fact you gave to support your position, but those facts don't lead me to agree with liberal nonsense about the Constution being nothing but a lens. (It's not a living-breathing flavor-of-the-month whatever-hippies-feel-like mood ring either!) It is true that common law decisions have no expiration dates and many common law decisions stand for centuries, maybe even indefinitely, but the US Constitution is far more than a lens through which we observe common law. The Constitution is the SUPREME law of the land. Yes, legislation supercedes common law decisions, but the Constitution supercedes everything. When the Constitution was ratified all common law contrary to the Constitution went out the window- likewise, when a constitutional amendment is ratified and becomes part of the Constitution. Yes, SCOTUS cites old common law cases, usually regarding matters on which the Constitution is silent, but any common law decision at odds with the Constitution is toast. I don't dispute that some old English common law decisions from colonial times may shed light on what the drafters meant by a particular legal phrase when deciding a constitutional question (they were speaking the same language after all), but like you said, that decision is only useful in the way that legislative history is useful, not as precedent which binds a justice by stare decisis.