 but that courts could consider that application on a case-by-case basis. However, Roberts warned, with significant portent, presidents have no presumption of immunity from unofficial acts in office. So, essentially, what the Supreme Court did here, and they did a great job with this, it was a 6-3 decision, it should have been 9-0. What they did is they said, when a president is conducting their duties as president, they are immune from prosecution. Why? Separation of powers.