What you can do legally on your porch is not relevant to hat a presidential or white house security team is trained & authorized to do.
Even on your porch in most states a trespasser with a weapon does not need to fire before you shoot.
Florida’s law states “a person who is not engaged in an unlawful activity and who is attacked in any other place where he or she has a right to be has no duty to retreat and has the right to stand his or her ground and meet force with force, including deadly force, if he or she reasonably believes it is necessary to do so to prevent death or great bodily harm to himself or herself or another or to prevent the commission of a forcible felony.”
I did not say trespasser. What if a stranger, 200 yards away, is trying out a new scope on their deer rifle and points it at your house. I don’t believe that even in Florida you would have the right to kill them.