In 2010 when I was doing this for the Key House Races, it was interesting to see how the composite polls from the "experts" diverged until a few weeks before the election, when they suddenly all came together. Some people attribute it to the undecideds remaining on the fence until the end. I attribute it to the "experts" astroturfing one side for as long as possible in the hope of swaying undecided voters to join the supposed masses, and then scrambling at the end to match reality.
We shall see.
-PJ
I remember in 1980 all the pollsters telling us Reagan and Carter were in a dead heat going into the election. The mistake they made was basing their assumption on the 1976 results which were abnormally slanted to the Democrat side due to the fall out of Watergate. I think 2008 was a similar year to 1976 thus the pollsters should be careful about making too much of the 2008 results in forecasting 2012.
I believe you’re right. The only poll that counts is the last one done prior to the election. That’s the poll these guys put their name on to sell their polling services in future years.