IANAL:
- to my understanding, qualified immunity of law enforcement or other government officials is from civil lawsuits; if I get injured while being arrested, I can't sue the arresting officer. It also only applies while they're actually doing their job, and not violating clearly established law.
- the presumptive immunity that SCOTUS claims the president enjoys is a shield from criminal prosecution. The definition of "official acts" is unclear but seems to extend to tweeting to a mob during one's term in office.
But further, I think in context the SCOTUS recognition of such an immunity was surprising because it came after the DOJ had maintained that even if Trump was committing crimes in office, it was against department policy to prosecute him while in office, and then once he's out of office and charges are pursued, the court claimed that charges still could not be pursued.
> the president can lose their immunity if it’s determined
Determined by the 6-3 conservative court? I think that's unrealistic.
He said in his first campaign that he could shoot someone on fifth avenue and not suffer any consequences, and it turns out he was right.