Thepretically they would need 34 states to sign off on that as a constitutional amendment, and theoretically even SCOTUS would have a hard time defending that,
But at this point who knows. The future is uncertain as ever, but it's certainly not looking great.
You act like SCOTUS would need to defend it. Assuming Thomas and Alito step down in the next 4 years, Trump has two open slots to fill with other younger bucks like he did in 2016, and without a Dem lockup in Congress to actually impeach anyone over their decisions, the decisions they make could theoretically stand unchallenged for decades.
Best case scenario would be a military coup, that tries to salvage what is salvageable of the current Democratic party, and use them to course correct, including a massive constitution rewrite.