1. The power of the presidency and no branch Congress in R hands has been lost. So there the forces in power including executive appointments are aligned against us and ready to be weaponized.
2. Social media suppression and the bias press have been emboldened.
3. SCOTUS refused to act when confronted with violations of the Constitution through usurping the powers of the state legislature. What makes you think they will act now?
4. Trump's approach of communicating to the public about election fraud and the ineffective actions of Giuliani and his team and the lunacy of the Lin Wood and Sidney Powell faction and the infighting with the Giuliani team allowed the press to portray this in the same manner as the birther issue and enabled mass suppression. Finally, Jan 6 was as effectively used as the Reichstag in 1933 Germany. All of this is now synonymous with election fraud in many people's minds.
Your last sentence is so true and bears repeating and I will end with it. (I think that the If is a more likely occurrence than not.)
“If SCOTUS refuses to grant the writ, the Republic is truly dead, and we fall back to the unspoken option of last resort.”