If I am wrong, I will admit it. But I believe that by Tuesday afternoon (BEFORE the debate) Obama will be leading most national polls (even Gallup with its 7 day look).
Why?
Biden's great debate will play a big role. Obviously it won't flip Republicans or that many independents, but it will do what it was intended to do: greatly energize the Democratic base. The fact is, after the debate a lot of Democrats were very depressed (I sure was). In many polls, "likely voters" are often determined by how excited you are about the campaign. When Democrats said they were down, they were LEFT OFF the likely voter lists. Thus, their support of Obama wasn't counted! With the excellent debate, these voters will be more enthusiastic and will be back on as: likely voters".
Remember, Obama's favorable/approval numbers are still quite good (in most cases his favorables are STILL better than Romney!)
Obama will need to have a good debate on Tuesday to keep the momentum going. I am sure he will.
Let's quit with the stressing out. It does not do anyone any good.
If you are concerned, donate, volunteer, organize!