I’ve added a new item of methodology for state polling aggregates: as many days’ worth of polling will be included from a given state as is necessary to produce a sample of more than 3000. The base line remains October 1. Apart from that, polls are being adjusted to incorporate the shift in the Real Clear Politics national average since the time they were conducted. Two developments are worth noting. We have a new swing state in West Virginia, where an American Research Group survey shows Obama with a shock 50-42 lead. This reverses the result from the last poll in the state (by Rasmussen) on September 24, so it should be treated with caution for the time being. Conversely, another American Research Group survey has McCain leading 49-46 in Missouri, which cuts Obama’s aggregate lead there from 2.2 per cent to 0.2 per cent.