Obama Rivals Say Des Moines Register Poll Can't Be Trusted

03/28/2008 02:45 am ET | Updated May 25, 2011
  • Marc Ambinder

The campaigns of Sen. Hillary Clinton and Sen. John Edwards take issue with the Des Moines Register poll's unusual methodology, which predicts turnout at this year's Democratic caucus to be 40 percent Independents and five percent Republicans.

The Des Moines Register poll adopts an unprecedented new turnout model for the caucuses, and its new poll is out of sync with the other polling done in the race.

When you look at Democrats who last time were 80% of the turnout, Hillary wins with that group by 6%, 33 to 27 for Obama and 25 for Edwards. And as David Yepsen points out, had their pollsters used the 2004 turnout model, Hillary would lead by 29 to 27, figures in line with the other polls.

The Des Moines Register Poll this time has 40% independent voters and 5% GOP voters in the poll when past independent participation has been 15% in 2000 and 19% in 2004, and the GOP has generally made up 1% of the vote. So they are depicting an unprecedented departure from historically established turnout patterns in the caucus. Under their model, only 55% of the caucus goers would be Democrats.

The other recent polls all show Hillary trending up and leading or within 1 point of the lead, and many show her moving up from a substantial deficit to tie and having the momentum in this race.

Insider Advantage, 12/28-12/19: Clinton 30, Edwards 29, Obama 22
Zogby, 12/27-12/30: Clinton 30, Edwards 26, Obama 26
Mason-Dixon, 12/26-12/18: Clinton 23, Edwards 24, Obama 22
Research 2000, 12/27-12/27: Clinton 28, Edwards 29, Obama 29
ARG, 12/26-12/28: Clinton 31, Edwards 24, Obama 24
Insider Advantage, 12/28-12/19: Clinton 30, Edwards 29, Obama 22

So we do not see this poll as accurately reflecting the trends we are seeing in other polls, on our nightly canvasses or in our own polls, and voters should understand this is a very close race, and that their participation on caucus night could make all of the difference.

Is the poll accurate? There are good reasons to think it is NOT.

-The poll was conducted during the holiday AND over the weekend. There is plenty of evidence that either of these would make it more difficult to obtain a representative sample. The combination makes the problem of obtaining a valid sample GEOMETICALLY [sic] worse.

-The poll is at odds with history. The poll says that 60% of Democratic caucus participants will be first timers. Usually, the number of first-time caucus goers is no more than 20%.

-The poll also says that 45% of those at Democratic caucuses will be Independents or Republicans.

The poll is at odds with other polls. Other polls show a close race with other candidates leading.

-Yepsen himself highlights the fluidity of the results rather than the horserace.

What does the poll really say

-The poll says the race is close. With a margin of error of +/-5, any of the top 3 Democrats could be in any of the top 3 positions.

-The poll says the race is yet to be decided. 34% say they could change their minds, and 6% do not express a preference. This means 40% are yet to decide.

-As Yepsen points out, 21% of those in the 2004 entrance poll [said they had made their decisions in the last 3 days -- something this poll cannot capture.