In law, groundebreaking decisions are often walked back by subsequent cases without totally overruling them. For example, if there was a decision that says j-walking is legal and it totally rocked the law enforcement community, it would be more likely for another court to come along and say, well, what they meant was j-walking is legal in the daytime. Then another could say, they only ruled that way on two-lane streets–it doesn’t apply to wide boulevards.
This has something to do with the technical aspect of court decisions–that even though they set precedent, they technically only set precedent according to their holding–which means that the facts that the court made its decision on have to be the saw for the law to apply.
In reality, new decisions tend to signal directions courts are going in–whether wider or narrower–with respect to a certain concept, and the holding isn’t the only thing that’s looked at.
Eventually, old cases get to a point where they’ve been picked away at so much that they might as well just be overruled. In my example, let’s say that after several later decisions, it comes out that j-walking is only legal in the day time with no clouds where there are no cars on two lane streets in a city with a population of less than 10,000 when there are stop signs at the end of each block, which must be no longer than 250 feet.
At that point, you just can’t rely on the force of the original case to mean anything about the law; the old rule has become a mere exception in the new scheme.
This is what has happened over time to our Constitution.
Some of it in ways that pleases some liberals, some not. For example, in general, Congress has become not a co-equal branch of government, but the sausage making part of a party’s power apparatus. It’s separate power is mostly for show. This is mostly self-inflicted wounds, but it also probably reflects the presidential aspirations of its most powerful members.
On the other hand, most of the limits powers of Congress are irrelevant one way or the other. The commerce clause has become a general police power clause. The war power has been almost entirely delegated to the President. The limited term copyright clause is meaningless.
I’ll keep fleshing out this list, but if you take a mental catalogue of all the ways that our constitution isn’t what it says it is, and doesn’t mean what it says it is, you’ll see that it’s basically meaningless at this point, and, strangely, this is mostly democratically approved.
Some of this is because some parts of the constitution are plainly stupid and need adjusting. Perhaps even the amendment procedure needs amendment, but the structure is held together with duck tape at this point.