Do many people rally vote according to debate results?
It depends on whether or not the voter in question is fully committed to a candidate or not.
If the voter is fully committed to someone, it may not make a huge difference. If they are still "shopping around" for a candidate, then it may. If they have no idea who they'll vote for, it probably does to a larger degree.
Other times it makes a difference is when the person is generally uncommitted, but discovers through the debates that one of the candidates holds some view which the voter finds anathema; or when a candidate really steps in a mess that he/she can't extricate themselves from, instantly delegitimizing that candidate for voters.
It wasn't during a debate, but an example of a moment that changed a candidacy instantly was when Howard Dean screamed. One moment, and it was over.
So, it depends, but generally, I think that it has been shown that the more a person is committed to a candidate, the less debates matter.
Debates have been the biggest factor this primary season by far. And it's not voting based on "debate results" per se. It's about who can articulate the vision for the country the best. A debate is a great place to find that out.
Newt has a huge surge in Rasmussen's national poll based on Monday's debate.
Plus, debates drive the rest of the discussion. It would be foolish to downplay the debates, especially this election cycle.