I think that's mythology.
Fifty years ago it was very difficult, compared to today, to get a lot of information on candidates or even to see them speak.
Today every little podunk stop a candidate makes is filmed and put up on YouTube. The point is: the more information there is already out there -- and there is exponentially more than ever in the last half-century -- the less any one event makes an impact.
And, as I said upthread, particularly in this cycle, I think the presidential debates are not going to change a single vote. By that time, the country will be even more polarized than it already is, and people will be even more sure that they want Obama out or they don't.
I think the presidential debates are not going to change a single vote.That's ridiculous. Perry went from 35% to 6% precisely because of the debates.