Most of SCOTUS is not in favor of “broad immunity”, for exactly this scenario. They want to make sure that Trump is never held responsible for his actions while in office, and that every President after Trump(if he doesn’t declare himself President for life) is criminally liable for everything. Trump has even said that he’ll have Biden prosecuted if he wins.
They are a real group. They’re part of a coalition with the White Women for Harris, who raised between $2-$8 million for Kamala Harris. Pantsuit Nation is rising up and New Balance Kingdom is going to match their work.