Party Weighting: The Great Unknown Of Election 2008
Posted Oct 17, 2008 at 10:13 AM by Maurice Berger
One way pollsters process raw data from samples is to filter it through party weighting models. In other words, a model that organizes voters by party and then weights the sample to reflect the percentage of likely voters from each party (as well as independents). With Democrat enthusiasm up this year, most pollsters give the party a considerable edge. In Rasmussen's weighting, for example Democrats outnumber Republicans 39.3% to 33.0%. For Zogby, it's closer: 38% to 36%. This weighting, in part (but several others factors are also at play), is responsible for the large swing in national numbers, from an Obama lead of +2% to +14%. PollTrack wonders: as national results are clearly narrowing, is Republican interest in the election gaining on Democratic? While Obama's campaign has fired up certain demographic groups --African-Americans, single women, young voters, for example--what of the traditional Republican constituencies: the over 65 set, Evangelicals, conservative Christians, and older white men? The latter groups tend to have exceptionally high turn out, literally making the difference for George W. Bush in 2004. There is anecdotal evidence that Evangelical voters, for a range of reasons--from anxiety about Obama to excitement about Sarah Palin--are growing increasingly enthusiastic about the Republican ticket. While some periodic polls (like CBS News/New York Times and Pew) show a very large lead for the Democrat, are these surveys underestimating the potential turn out of groups that--as a rule--vote in consistently and often extraordinarily numbers? Pollster John Zogby notes: "What troubles me is when I see some of my colleagues have 27% of the respondents that are Republicans. That's just not America, period. [Party affiliation fluctuates over time] it doesn't change "day-to-day, and it never fluctuates by eight points in a short time period." Will the 2008 election break the mold--resulting in an unprecedented jump in Democratic turn out--or will Republican and conservative voters also show up in significant numbers, thus drawing the race much closer (especially in battleground states that already tilt Republican, such as MO, NC, FL, NV, CO, and OH)?
