Congress could, if it so chose, to replace the entire Supreme Court, or reduce the number of judges to three, consisting of Scalia, Thomas, and Rhenquist. It can restrict the jurisdiction of the court from certain subject matters.
In practice, we've allowed the US Supreme Court to be the highest and final authority in all things. But if you look at the Constitution, Congress has the power to take the Supreme Court down to a toothless tiger if it wants.
Article V: The Congress, whenever two thirds of both Houses shall deem it necessary, shall propose Amendments to this Constitution, or, on the Application of the Legislatures of two thirds of the several States, shall call a Convention for proposing Amendments, which, in either Case, shall be valid to all Intents and Purposes, as part of this Constitution, when ratified by the Legislatures of three fourths of the several States, or by Conventions in three fourths thereof, as the one or the other Mode of Ratification may be proposed by the Congress; Provided that no Amendment which may be made prior to the Year One thousand eight hundred and eight shall in any Manner affect the first and fourth Clauses in the Ninth Section of the first Article; and that no State, without its Consent, shall be deprived of its equal Suffrage in the Senate.
And tell the SCOTUS how they must interpret the Constitution, and maybe fix a few other things - it has never been done ... but.
It is not merely a question of politics or them being wrong. The Supremes have lost it. It was clear then that it was time to get those bozos out of there.
A friend who chaired the Marin County, California ACLU chapter for six years tole me this death penalty ruling sucks, so there is little disagreement on judicial competence here, and competence is not a partisan issue. The circuit court judges' group letter was legally devastating. The Supremes have lost the respect of the legal profession and their fellow judges.
This recent death decision is IMO more a matter of "Those that the gods would destroy, they first make mad."
Then California Assembly Speaker told then California Supreme Court chief justice Rose Bird, a year before she was removed from office for trying to abolish the death penalty by judicial fiat, "Rose baby, some people really should meet their maker sooner rather than later." She didn't take the hint. Two other California supreme court justices went down with her.
The only real question is how much more damage these bozos do before they leave, or are removed from, office.