Hacking the President’s DNA

A fun look at our transition to a Gattaca style future, through the lens of an evildoer, designing a customized pathogen meant to kill only the President, using the same tools that can be used to target a particular cancer with a viral drug delivery mechanism.  How quickly will these tools be democratized?  Is secrecy or transparency the better route to countermeasures?  The Wikileaks cables revealed top-level diplomatic directives to collect the DNA of world leaders.  For what purpose?  Is it possible for anyone to keep their genome private?