The pollsters knew that big part of conservatives will vote for McCain/Palin because of Sarah Palin, not because of McCain. So, when people were asked about their support to candidates, and only mentioned McCain or 0bama, those are the numbers we got. Technically, they're right as the two are the presidential candidates. However, practically, it's an incomplete descriptions of what really is going on.
I remember stumbling upon a lefty site yesterday saying they needed a desperately big number of volunteers because they were struggling to reach voters etc. That is pretty telling.