They would need to take out all his children and grands too.
Note to NSA; this is only fiction fantasy and not the type of thing we would actually carry out ourselves because Soros is such a dear friend of your boss though your leader wouldn't think twice about doing it whomever stepped in his way including you, too. Ask the following people:
http://www.nachumlist.com/deadpool.htm
Sorry. I guess you can't after all...