Stats Geek: Presidential Polling or, the Fat Lady is Warming Up

Hello, my name is Alan and I’m a stats geek. I admit it, I like to play with numbers.

When I learned linear regression as part of one of my MBA classes I immediately set about trying to figure out how to use it to pick horses at the track. I hardly ever gamble but I liked the idea of trying to use numbers to predict winners. (And because I know you’re curious, it did work, but not any better than someone who spends time at the track and knows how to read a racing form well.)

What I really like to do is look at numbers to see if I can find something that someone else isn’t seeing.

With the presidential election just days away I can’t help myself, I just have to look at these presidential polling numbers. Frankly, the predictions we’ve heard from the television talking heads haven’t been all that great the last couple of elections, so I wanted to look at the numbers myself.

At this point the talking heads are all pretty much declaring an Obama victory and what I wanted to see is if McCain can still win this election. My conclusion, barring a seismic shift on Election Day unlike we have ever seen before, I just don’t see how that happens.

Warning, if you’re not into this numbers stuff, now is the time to leave.

For simplification purposes, I used the polling numbers from CNN’s website. It currently shows Obama winning with 291 electoral votes (270 needed to win). Those numbers are more conservative than many other places you will look.

Further, it breaks it down to show Obama with 203 votes solidly in his column, 88 leaning his way and 84 as tossups. McCain has 163 solid and 41 leaning his way.

As I looked at the numbers I began with some assumptions:

First, for McCain to win you have to assume that people will change their minds and the actual voting will be much closer than the polling now shows. It all depends on which candidate builds the momentum the next few days. Right now that looks like Obama but with the right attack ad from McCain’s camp, it could change in a moment’s notice. Let’s say McCain does pull a rabbit out of the hat, it does go his way and he closes things by three percent before Election Day.

Second, I believe that some voters are lying when they say race isn’t an issue. I think they’re saying to the pollsters that they will vote for an African-American, when in fact they will vote just the opposite way behind that pulled curtain. For the sake of argument, let’s put that at one-half percent.

In addition, there is a margin of error in these polls in the range of four percent. Here, let’s say the numbers are off for whatever reason by another one-half percent.

A quick mathematician will add those percents up and see that we are at a four percent swing to McCain by Election Day.

We’re already making some pretty sizable assumptions so, what the heck, let’s make one more. Let’s assume McCain will carry all of the states that CNN shows as either solidly for him or leaning his way. That puts his electoral total at 174 (again, 270 is the magic number.)

From here, it’s pretty simple, we look at the polling and see which states in Obama’s column are showing a four percent margin or less in his favor.

There are two states sitting at less than four percent, Indiana and North Dakota, with a combined electoral vote of 14. That puts McCain up to 188.

Then there are two states sitting at exactly a four percent difference, Ohio and Florida. As we’ve learned from the last two presidential elections, those can be the deal breakers. Florida won it for Bush in 2000 and Ohio did it in 2004. Combined they represent 47 electoral votes. If both swing McCain he’s now up to 235.

To get to 270, McCain needs to carry all of that plus some combination of the states that are currently polling between five and nine percent for Obama. Those states include New Mexico (five percent and five electoral votes); Nevada (seven percent and five votes); Colorado (eight percent and 9 votes); Wisconsin (eight percent and 10 votes); Pennsylvania (eight percent and 21 votes); and Virginia (nine percent and 13 votes).

It may be difficult for McCain to carry Pennsylvania because Obama’s running mate, Joe Biden, is originally from there and still has ties to the state. Without it, McCain has to win nearly all of the others listed.

Keep in mind as well, that there are states that McCain leads by four percentage points or less himself. The more time he campaigns in those states, trying to keep them in his column, the more challenging it becomes to pull these other states into his column.

It’s difficult to believe that McCain can close the gap and carry all three of the states of Florida, Ohio and Pennsylvania. If he loses even one of those he has to win almost every other state in which he is within even 10 percentage points.

Can McCain pull it out? Certainly, we just need to remember President Dewey to know that.

It's never over until the Fat Lady sings, but she's definitely warming up.

And if McCain does somehow pull it out, this is one stats geek who can’t wait to look at the numbers and see how it happened.