 You know, normally these are very controlled affairs. This will be even more so because of the very tight rules, the fact that each candidate will have their microphone turned off while the other is speaking. Those things ought to, you would expect, mean that this will be a fairly controlled, fairly well prepped event. But with both of these men, there is a sense that there is something unpredictable. John Sudworth there in Atlanta. Full coverage of the debate in later editions of the Newsroom.