GOTV and likely voters

Via realclearpolitics--This is what the the Washington Post wrote on Sunday:

Sen. Barack Obama's campaign intends to avoid a (2004) repeat by building an
organization modeled in part on what Karl Rove used to engineer Bush's victory:
a heavy reliance on local volunteers to pitch to their own neighbors,
micro-targeting techniques to identify persuadable independents and Republicans
using consumer data, and a focus on exurban and rural areas. But in scale and
ambition, the Obama organization goes beyond even what Rove built. The campaign
has used its record-breaking fundraising to open more than 700 offices in more
than a dozen battleground states, pay several thousand organizers and manage
tens of thousands more volunteers.

And this is what Gallup has to say regarding how this get out the vote strategy may affect its survey-weighting methods:

Likely Voter Estimates
"Obama's current advantage is slightly less when estimating the preferences of likely voters, which Gallup will begin reporting on a regular basis between now and the election. Gallup is providing two likely voter estimates to take into account different turnout scenarios.
The first likely voter model is based on Gallup's traditional likely voter assumptions,which determine respondents' likelihood to vote based on how they answer questions about their current voting intention and past voting behavior. According to this model, Obama's advantage over McCain is 50% to 46% in Oct. 9-11 tracking data.
The second likely voter estimate is a variation on the traditional model, but is only based on respondents' current voting intention. This model would take into account increased voter registration this year and possibly higher turnout among groups that are traditionally less likely to vote, such as young adults and racial minorities (Gallup will continue to monitor and report on turnout indicators by subgroup between now and the election). According to this second likely voter model, Obama has a 51% to 45% lead over McCain. "
(Click here to see how the race currently breaks down by demographic subgroup.)


And for the "registered voters" sample, the figures are 50% Obama, 43% McCain. This means that the different weighting method leads to three different forecasts, with margins of victory ranging from a 4 to 7 percent lead in favor of Obama. With sampling errors of roughly 2%, the weighting method will be crucial in predicting heavily contested states such as Virginia.