I didn’t think it possible that US politics could get any worse, but it has. Those employed to investigate such matters have amassed substantial evidence that Trump plans to remain president at all costs. He will likely contest the election to the extent that it would be up to the Supreme Court, stacked 6–3 with conservative judges. He expects the Supreme Court to decide the election in his favor, just as it did for George W. Bush in 2000.
As I see it, the democrats can overcome this scenario by landslides in the Senate and House of Representatives, in which case the legislature could impeach Trump, either before or after he takes office, as the case may be. The new Congress meets the first business day after January 1, 2021, and has until January 20 before the inauguration.
Without a landslide, the Senate, composed of shameless lemmings, will do Trump’s bidding. Even if there is a landslide in both houses, nothing will happen unless the new Democratic Congress is willing to expand the Supreme Court to allow a Democratic president to appoint additional justices. Beyond that, it can do little other than impeach, which is probably not in the cards.
A more drawn-out, iffy course of action would be an amendment granting Congress the power to nullify Supreme Court decisions by a 3/5 or 2/3 majority of both houses. A slightly more limited congressional power would allow nullification only if 2, 3, or 4 justices dissent from the decision. The amendment could limit Congressional power to nullify judgments only when one or more of the dissenters vote to submit the disputed issue to Congress.
At first blush, such an arrangement might not even require a constitutional amendment. The Constitution empowers Congress to establish rules for federal courts, create inferior courts, etc.
There is a problem, however, regarding the Article III phrase “judicial power.” The annotations to Article III at the Cornell University website cite US Supreme Court decisions holding that final judgments of the Court are not reviewable by the other two branches. Chicage & Southern Air Lines, Inc., v. Waterman S.S. Corporation. Civil Aeronautics Board v. Same, 333 US 103 (1948). If my hypothetical statue allows Congress or the Executive to review a judgment of the Court, it has no jurisdiction over the case.
To change this would require a Constitutional amendment.