let's do the seal team six hypo. president orders st6 to assassinate a political rival bc rival is a threat to national security. possible this is absolutely immune under pres's commander in chief power. if it's not, then it gets presumptive immunity (which may be absolute anyway)
Biden would have such a demonstrably well justified claim on this ground as to Trump. Though he wouldn’t even have to present the rationale in court. Then there’s Ginni and Clarence, the Alitos, a bunch of Members of Congress. That’s just at the top levels of the federal government.