CNN added this "Special Note" to the poll results:
SPECIAL NOTE OF CAUTION #2: The sample of debate-watchers in this poll were 31% Democratic and 33% Republican. That indicates that the sample of debate watchers is about eight points more Republican than an average CNN poll of all Americans, so the respondents were more Republican than the general public.
http://www.cnn.com/POLITICS/pollingcenter/polls/3262
This poll had a Republican bias that should be considered in the results.