If progressive cases had come to the Supreme Court too early...

Would they simply have been shot down? For example, segregation was upheld under the “separate but equal” ruling for decades, until overturned by a later decision. Imagine if any of the following had been brought before the SCOTUS in the nineteenth century: school prayer, abortion, a Miranda-like case, public Christmas displays, etc. If it was on record that the SCOTUS had addressed the cases and ruled against them, would those causes have been thwarted indefinitely? And would that demonstrate that the Justice’s rulings were based as much on prevailing social norms as any fixed writ of law?

Until the 14th Amendment passed during Reconstruction, federal law was clear that the Bill of Rights applied only to the federal government, and not to the states. If Massachusetts wanted to make kids say their prayers in school, the federal constitution had no impact on that decision. It was not until (approximately, IIRC) the 1880s that the federal courts began applying the BoR against the states under the theory that due process included (some or most) of the guarantees of the BoR.

Nevertheless, your point is well taken. Impatience for immediate results may indeed lead to the extension of injustice rather than its elimination.

I agree, FWIW. Minty, a minor hijack – as has been beaten into the ground bloodily around here, the 14th Amendment’s Due Process Clause has had a lot of influence on “rights” cases generally. Could you briefly address the Privileges and Immunities Clause, along the same lines? I see a lot of discussion about it on a theoretical basis, but have never seen a leading case cited as relying on it.

That’s because the Privileges and Immunities clause (“The Citizens of each State shall be entitled to all Privileges and Immunities of Citizens in the several States”) has been interpreted to mean nothing more than that the government can’t discriminate against you just because you’re a citizen of another state. The Findlaw annotation provides a nice summary.