Breaking it Down: The Polling Mess

Yesterday, the Dispatch wrote this about the new Rasmussen poll showing Rob Portman up by 4 on Lee Fisher:

Rasmussen’s explanation of the party ID crosstabs hardly seems to lead to a 4-point Portman lead, unless its sample is overwhelmingly Democratic:

“Portman, a former congressman and George W. Bush administration official, has support from 85% of Republicans, while Fisher is backed by 69% of Democrats. Portman leads by 20 points among voters not affiliated with either major political party.”

Well, with Rasmussen’s numbers out today showing Kasich up only by three on Strickland, do these crosstabs look any better from a Party ID weighting perspective?

Not so much.

Kasich wins 83% of the GOP vote.
Strickland wins 72% of the Dem vote.
Kasich wins Independents by 19%.

And we’re supposed to believe Kasich is up by only 3%? Once again, that’s only possible if the sample is overweighted with Democratic votes.

So let’s try a little experiment of our own.

If we use the highest profile Exit Poll from the 2008 election, as provided by CNN, that broke down the number of GOPers, Dems, and Independents that voted in the Presidential, and applied those ratios to this result, what would happen?

In 2008, per CNN, 5,608,789 Ohioans voted. 39% were Democrats, 31% were Republicans, and 30% were Independent.

As you can see, if we apply Rasmussen’s gubernatorial choices by Party to the Party ID model provided by CNN in 2008, we get a vastly different result. And that doesn’t even take into consideration the all too likely probability that the 2010 breakdown by Party will likely be more favorable to Republicans than the Year of Obama.

Now, is this formula perfect? Of course not. We’re using two different polls, and we’re unable to determine whom the undecideds in Rasmussen would vote for. But this does give us a more realistic perspective of what to expect if Rasmussen’s breakdown by Party ID is correct.

The one pollster so far that has most closely reflected Party ID as it broke down in 2008 has been the Democratic polling firm PPP. Unfortunately, we haven’t heard from them since late June.

This all goes to show you, gauging a race by a single poll, while very interesting, isn’t likely to give you a real reflection of the race. Instead, we need to gauge polls as an aggregate. The bad news there? Four of the past six polls have been Rasmussen.

PPP, Quinnipiac, Ohio Poll, and Survey USA need to step it up.