Not going to happen if he or she is a left over democrat. It works to well in their favor to have every news outlet stating that it is a Republican leak.
We should only be so lucky that Novak's source is a "leftover Democrat." That would be like manna from heaven.
My view is that this person is going to be found out. Whether Novak discloses the name sotto voce to the "right person," or it happens through straightforward investigative work by the FBI, it'll happen. If the source is smart, he or she will save us all some agony and come forward now.