In an effort to measure the impact of Obama’s candidacy on the electorate, especially among young and minority voters, Gallup has begun publishing presidential tracking poll results based on two different “likely voter” models. The first is the traditional model, which designates likely voters based on how they answer questions related to both their current intention to vote as well as their past voting behavior. In today’s tracking poll, Obama registers a seven point lead over McCain using this model. The second model, Likely Voters II, designates likely voters based solely on their current voting intention, and in this way attempts to account for the intensity of interest, and mass of new voter registrations, among groups that typically do not vote in high numbers, including the young and racial minorities. Using that model, Obama has a 10-point lead.
One of the big unknowns in this cycle has long been what the electorate will look like on Election Day. Gallup deserves credit for trying to apply a model that accounts for the electorate’s likely new complexion. It’s also understandable why they’re hedging their bets by going with two models, because we simply can’t be sure who will vote.