What happens to laws in the US that the SC finds unconstitutional?

When the SC finds a federal law unconstitutional, what exactly happens?

Does someone actually delete the law from a book somewhere?

Or is it just that an asterisk is put by it (metaphorically at least) such that everyone now knows they needn’t try to follow that law since if it came up, the courts wouldn’t enforce them?

In other words, is it literally no longer a law, or is it simply rendered a kind of “powerless law”?

The latter.

The statute (or regulation, state constitutional amendment, executive order, or whatever) remains on the books until/unless removed by legislative (or other issuing authority) act. Whyat the result of the court decision actually is, is not that it is “struck down” as the press would have it, but that SCOTUS, and every court which is obliged to follow SCOTUS precedent, which is all of them, decline to enforce that law in civil suits or as against violators, as it flies in the face of the supreme law of the land, which they are sworn to make their rulings by.

Well, it can be more complicated than that, as in the case with Brown. Some states refused to comply and even the SCOTUS gave the school districts some undetermined amount of time to desegregate, even if they were supposed to do so “with all deliberate speed”.

Even more than that, here’s a 2004 document (warning: pdf) that talks about segreation laws that were still on the books50 years after Brown.

I wonder if I’m the only one who interpreted the post title as: “laws in the US that South Carolina finds unconstitutional.”

Ohio, if I am not mistaken, still has a flag buring law on the books, even though not enforceable.

In comparison many so called “silly laws” are still technically on the books, never having been officially repealed. You know, you can’t walk a chicken on main st. after 5 o’clock, etc.

While courts would not make a mistake, as least I have never seen one in print, that cites a Struck down law as active, a layman might take it that way in research, not knowing how to conduct it.