Many Many years ago I read a book about Merlin and King Arthur.  My daughter, now a young woman has heard me speak of this book and wants to read it.  I can not,  for the life of me remember the name or the author. 

The story is set in modern times NYC.  Arthur is running for Mayor, Merlin had been kept captive in a cave in NYC and has just been set free.  Morganna is a crazy old woman who watches the world through her TV and is determined to ruin the election.  Can anyone help me figure this one out?  I would be so grateful! 

I'm not sure of the book , but here is a list of books about King Arthur by Century...hope this helps :-)

http://en.wikipedia.org/wiki/List_of_books_about_King_Arthur

Could the author be Peter David? It's a trilogy (Arthur is mayor in the first book and then becomes President of the United States):

Knight Life

One Knight Only

Fall of Knight

I agree with Karen, sound's like the Knight trilogy by Peter David.  Those were good, funny, and good plots.  I liked Merlin.