every time i follow a thread about a poll, someone says that Obama's good day will drop off tomorrow... however, it doesn't seem to change anything... i may be wrong, but i have that perspective... McCain is not having any really good polling days...
Sometimes it does, and sometimes it doesn't. Sometimes a good day is replaced with an even better day. We don't know that until we actually see the next day's poll.
But it is extremely rare in Rasmussen's poll for any one candidate to poll 7 points (my calculation) to 11 points (somoene else's cauclation) better than the other candidate in a single day. This happens in all polls approximately 5% of the time. Something like this apparently happened in Obama's favor on Tuesday night in Rasmussen's poll. If it was a real trend rather than statistical noise, we would have expected to see the same thing in other contemperaneous polls, but no such thing happened.