Could Congress create a court higher than the Supreme Court?

Question

Could Congress create a court that could overrule SCOTUS decisions?

Answer 1

No

The judicial Power of the United States, shall be vested in one supreme Court, and in such inferior Courts as the Congress may from time to time ordain and establish.

Any courts the Congress creates are, by definition, inferior.

Of course, Congress can overrule a SCOTUS decision by passing a law to that effect,unless the decision defines a right under the Constitution. So they couldn’t overturn Roe but they could overturn Dobbs. It’s largely the gutlessness of Congress in grappling with controversial issues that has put SCOTUS in the position of lawmaker.

Answer 2

To the title question: sort of.

Congress has almost complete control over the appellate authority of both SCOTUS and other federal courts; indeed they control the very existence of federal courts other than SCOTUS. Only those matters specifically enumerated in the constitution are immune from control. They can remove anything else, even for cases that are currently under their consideration. SCOTUS has upheld this, asserting that it only has mandatory jurisdiction over those things expressly enumerated in the constitution, or on general matters of deciding constitutionality. So they could decide if a law that strips them or another court of jurisdiction is constitutional, but if they determine that it is then that jurisdiction is stripped and the relevant courts, potentially including themselves, cannot hear or rule on the case.

As such, Congress could, in principle, create a de facto "new" SCOTUS by stripping the SCOTUS of jurisdiction and granting it to some other court, or none at all. And they've tried the none at all option before! To my knowledge, those of any particular substance and extent have all been overturned as creating some other constitutional issue, though. The most recent example is the Military Commissions Act of 2006, which was a direct attempt by Congress to stop all federal courts from hearing cases from Guantanamo detainees. This was ruled unconstitutional in Boumediene v. Bush. The implication seems to be that stripping the entire federal judiciary of jurisdiction is likely to be a problem; but stripping just some of the federal judiciary can be okay. As such it is possible, though far from clear, that this proposed "new SCOTUS" would be upheld as constitutional. However, they still could not overrule SCOTUS on anything, including what is/isn't constitutional. Its place in the federal judiciary would just present a greater obstacle to the involvement of SCOTUS in cases going forward; as a side effect this would probably also make it harder for SCOTUS to overrule itself.