Medications might also cause a drop in blood pressure. Beta-blockers and nitroglycerin, used to treat heart disease, are common culprits. Diuretics, tricyclic antidepressants, and erectile dysfunction drugs can also cause hypotension. Some people have low blood pressure for unknown reasons.
Theoretically, then, the President can probably pardon him/her-self for any Federal crime â but this only prevents actual prosecution for that crime, not impeachment for the crime itself. Prior Answer, to the hypothetical of the VP murdering the President and then pardoning himself:
They also weighed whether presidents should be allowed to pardon people only after they are convicted. They decided not to add that restriction, because they thought a quick pardon of a captured spy would induce the spy to divulge military secrets. They decided not to limit the presidents power in any way.