Instant-reaction polls conducted by CNN and CBS News suggest that Mitt Romney was the winner of the first presidential debate. … A contradictory data point comes from Google, which is experimenting with online surveys and which collected many of its responses as the debate was under way. …
There is not a lot of empirical research on the relationship between instant reaction polls and their eventual effect on the head-to-head polls. However, these were strong numbers for Mr. Romney where comparisons to past post-debate polls are available. [cont.]
Nate Silver, FiveThirtyEight