The new CNN/Time poll. What are we going to do with it? The top-line of the poll says Obama leads by 5, 49 to 44 but everything underneath says that poll has little basis in reality.
In 2008 candidate Obama won Ohio by 5 percentage point while winning Independents by 8 points. In today’s CNN/Time poll, Mitt Romney leads with Independents by an incredible 13-points but is down overall by 5-points. That is simply not plausible.
The party ID in this poll was D +9 (Dem 37, Rep 28, Ind 29). This compares to D +8 in 2008 (Dem 39, Rep 31, Ind 30) and R +5 in 2004 (Dem 35, Rep 40, Ind 25). There is no chance the Democrat turnout advantage will exceed Obama’s 2008 best in a generation turnout which we write as D +8 based on the CNN party ID generally used. This is even though the actual 2008 party ID was really only D +5 making this D +9 that much more unrealistic.
Early voting and the likely voter screen
Early voting is creating a unique problem for polling organizations this year. Since Democrats tend to vote early, you see the Democrat candidate typically leading by wide margins in early voting. According to the CNN survey “respondents who say they have already voted, Obama holds a two-to-one lead over Romney, 60% to 30%.” So we know upfront in early voting there is an overwhelming number of Democrats.
When it comes to polls, all voters who said they already voted make it through the likely voter screen and end up in the final results. Approximately 17 percent of the respondents were early voters while 83% had yet to vote. This means a 17% segment of those polled are guaranteed to make it through the likely voter screen and we know that group supported President Obama by a 2-to-1 margin. This inherently over-samples Democrats which practically guarantees a favorable result for Democrats. The problem with early voting and polling ahead of election day is the results will skew in favor of the party with the higher early turnout, in this case the Democrats. That’s one of the ways you end up with a party ID of D +9 when there is no chance of that turnout occurring on election day.
It was nice of CNN and Time to spend the money to run a poll of all-important Ohio, but I think this poll did little more give false hope to Democrats who are likely in for a rude awakening on election night thanks to unrealistic polls like this one.