[@LordOfTheNight]
No earthly clue if you want anyone for this but does this plot reference ”The President’s Vampire” or “Blood Oath” by Christopher Farnsworth?! 

A vampire serving the president after being spared by Andrew Johnson and this said vampire works for the president and his successors? Cause that sounds like the vampire’s last name might be Cade or I’m losing my mind. 

Sorry just wanted to say something.