I often hear liberals complain that pollsters don’t include cells phones (or enough cell phones) in their sampling, and that they are therefore skewed against Democrats. One obvious argument in support of this theory is that younger people tend to favor the Democrats and they tend not to have land-line phones. Nate Silver takes a look at the pollsters and finds a 2.8% bias against Obama for polls that do not include at least some cell phones in their samples. Other recent studies have found smaller biases or none at all.

Perhaps the most interesting finding in Nate’s analysis is that Gallup polls over the course of the year have averaged out to a 0.6% bias toward McCain over the mean. It is the only pollster that includes cell phones to show a bias in McCain’s favor. That makes their finding today all the more significant: Obama 50, McCain 44. That matches up well with today’s Research2000 poll: Obama 50, McCain 42.

If the assumption is correct that McCain will pull in about 70% of undecided voters, the result would be Obama 52, McCain 48, or Obama 53, McCain 47. Throw in some third party voters in there for shits and giggles, but you get the idea. However, these national polls can be deceptive. In the Research2000 poll, we see the following regional results:

McCain/Obama

NORTHEAST 33/60
SOUTH 52/39
MIDWEST 38/53
WEST 40/52

GEOGRAPHIC BREAKDOWN:

Northeast:
DC, ME, VT, NY, MD, PA, CT, DE, MA, NH, RI, WV, NJ

South:
FL, NC, SC, AL, MS, GA, VA, TN, KY, LA, AR

Midwest:
IL, MN, MI, OH, WI, IA, MO, KS, IN, ND, SD, OK, TX, NE, CO

West:
NM, CA, OR, WA, AK, HI, MT, ID, UT, NV, AZ, WY

When you factor in that the Midwest number includes Texas, Oklahoma, Kansas, Nebraska, and the Dakotas, Obama’s 15-point lead looks even bigger. This is especially true because, other than Illinois, it is not expected that Obama will win any of the Midwest states by huge margins. For this reason, there is very little in the Blue States to offset McCain’s big numbers in places like Oklahoma (where McCain leads 63-36) or Kansas (where McCain leads 59-40). If Obama has a 15-point lead in the Midwest despite his pitiful performance in the Plains states, then he is truly sitting pretty.

Meanwhile, McCain leads only in the South. And McCain must carry every southern state, including Virginia and Florida (where Biden and Obama are campaigning today) in order to have any chance at victory. The polls may tighten up again, as they have in the past. But the national polls are deceptively close because of the regional differences.