Friday :: Oct 8, 2004

Gallup's Latest Polls In Three States May Undercount Kerry's Surge


by Steve

Gallup released three state polls yesterday for CNN and USA Today. In all three key states, they reported that Kerry had closed the gap with Bush, with Bush holding three point leads over Kerry amongst likely voters in Wisconsin and New Mexico, and with Kerry and Bush tied in Colorado.

Yet when you look closely at the party ID of the likely voter samples that Gallup used in each state, you find that Gallup, once again, is basing its likely voter poll results on samples that when compared to the actual 2000 exit polls have a higher number of GOP respondents than may be warranted.

New Mexico
Poll Done October 3-6, 2004
673 Reported Likely Voters (LV), 669 Actual In Sample
Results:
Bush: 50%
Kerry: 47%
Nader: 2%

Party ID From LV Sample Per Gallup
Rep 258 (38%)
Ind 130 (19%)
Dem 281 (42%)

2000 Exit Poll Party ID

Rep: 32%
Ind: 25%
Dem: 43%

So the latest Gallup LV sample, which shows Bush ahead by 3% contains a 4% edge for Democrats when in 2000 the actual turnout edge for the Democrats on Election Day was 11%, nearly three times what Gallup built their poll on yesterday. If Gallup's LV sample from yesterday was recalibrated to more closely reflect the 2000 exit poll results, the purported 3% edge for Bush in yesterday's poll would disappear. Plus, note how Gallup undersampled Indies and oversampled GOP respondents in yesterday's LV results, when compared to the 2000 exit poll results.

Colorado
Poll Done October 3-6, 2004
667 Reported Likely Voters, 663 Actual in Sample
Results:
Bush: 49%
Kerry: 49%
Nader: 1%

Party ID From LV Sample Per Gallup
Rep 260 (39%)
Ind 198 (30%)
Dem 205 (31%)

2000 Exit Poll Party ID

Rep: 36%
Ind: 29%
Dem: 35%

Gallup yesterday said Bush and Kerry were tied, based on a LV sample that contained an 8% edge for the GOP. Yet in 2000, the exit polls showed only a 1% GOP edge. Therefore, if the Gallup LV sample from yesterday's poll was recalibrated to reflect the 2000 exit poll results, Kerry would be ahead in Colorado as well.

Wisconsin
Poll Done October 3-5, 2004
704 Reported Likely Voters, 694 Actual In Sample
Results:
Bush: 49%
Kerry: 46%
Nader: 2%

Party ID From LV Sample Per Gallup
Rep 246 (35%)
Ind 213 (30%)
Dem 235 (33%)

2000 Exit Poll Party ID

Rep: 32%
Ind: 31%
Dem: 37%

Again, Gallup yesterday reported that Bush was ahead of Kerry by 3% amongst likely voters by using a sample that had a 2% GOP edge. Yet in 2000, Democrats had a 5% edge over the GOP on Election Day. Based on that seven percent swing between what happened on Election Day 2000 and what Gallup estimated yesterday, it is very possible that Kerry is either tied or ahead in Wisconsin, and not behind by 3%.

The short version: If Gallup's LV sample was recalibrated to more closely reflect what actually happened in 2000, Kerry is probably clearly ahead in all three states.

Steve :: 12:34 PM :: Comments (14) :: Digg It!