Something I never understood

Why didn't The KGB try to turn Abbie? It seemed to me like there were a lot of chances to do so, but they never did. There was a book a read about 10 years back (can't remember the name of it) it was written by a former Russian intel officer and it was his belief that the biggest mistake the KGB made during the 60's was not funding left wing american groups. He also mentioned Abbie a few times in his book that his name came up at meetings in East Germany as someone they should have turned, but i guess they never got around to it.

http://www.youtube.com/watch?v=xETgGym8cnE