@RABEL222,
Lots of changes happen from week to week. We saw that in the last campaign season. Those weekly changes don't seem to translate into an election victory, unless one is caught in bed with either a live boy or a dead girl.
What is predictable is changing demographics. Ethnic and racial minorities are increasing. It's reasonably predictable there will be more lower income voters in the future, as well as more dependent on the government for income. I'm inclined to go with Robert on this one.