Riots would enflame in greater quantities than before. Among them would be Portland and Seattle (though I guess they technically never ended in either of them), but you would also expect them to spark in Washington DC, New York City, Los Angeles, San Francisco, Minneapolis, and likely other places too. The media would fan the flames of course and declare Trump a tyrant and a fascist who did indeed refused to concede defeat like they said he would, and has seized power, as well as for all the leftists and RINOs in Congress to scream and call foul and demand justice, maybe even call for another impeachment.

Honestly, it's for all these reasons why the Supreme Court will NOT step in and determine anything. Those that have any say will not allow the investigations into voter fraud to go that far; even if they know everything Trump says is true and that the election has been stolen, they would still screw him over if only because they fear the pandemonium that would ensue. Hell, even if it did get that far, the Court itself might feel pressured to rule against Trump for those reasons.