What you need to know:
- Gallup tracking poll is conducted by making phone calls to voters.
- Political scientists have begun to doubt the accuracy of the polls.
The accuracy of opinion polls showing a slim lead by United States Republican candidate John McCain over Barack Obama has been put in doubt following the discovery that the pollsters did not take into account a recent surge in Democratic Party membership.
It is now emerging that the opinion polls most famous in Kenya for the storms they caused in the period before the General Election cannot be trusted to truly reflect Mr Obama’s chances of winning the November 4 presidential election.
That, and former US president Bill Clinton’s endorsement of Mr Obama could have a bigger advantage than expected over Mr McCain.
According to an article on www.huffingtonpost.com, the polls were conducted using a higher sampling of Republican voters than in July.
This year alone, the Democrats have a lead of 11 million registered voters over Republicans, and have been adding to that advantage through a robust field operation leading to the suggestion that the pollsters from Gallup have been over-sampling Republicans.
The Gallup tracking poll is conducted by making phone calls to voters and the article says the pollsters have been using data from July and their lists are therefore not updated.
In the latest poll by Gallup published on Thursday, an equal number of Republicans and Democrats were surveyed from September 3-5, compared to a 10-point Democratic identification advantage two weeks ago.
The skewed make-up of the polling pool resulted in a 5-point lead for McCain in the September 5 tracking poll.
Meanwhile, the new CBS poll features a 6-point swing in partisan composition toward Republicans, which plays some role in the poll’s two-point lead for Mr McCain.
Finally, the latest USA Today poll, which claims a four-point edge for McCain, was arrived at after a 10-point swing in partisan makeup toward GOP respondents.
“Monday’s USA Today poll had a 48-47 split between Democrats and Republicans surveyed. That represents a nearly 10 point shift in party identification toward Republicans since USA Today’s July polling. When asked for comment, USA Today polling editor Jim Norman wrote that “it’s possible” that their latest sample includes too many Republicans.
Though he added, “it’s also possible that we have too many Democrats,” because “there’s always the chance of an over- or under-representation” in polls,” reads the article in part.
Political scientists have also begun to doubt the accuracy of the polls which showed a first time lead for 72-year-old McCain.
Mr Alan Abramowitz, a political scientist at Emory University, was said to be highly sceptical of the three new Gallup, USA Today and CBS polls.
On the CBS poll, which showed a statistically insignificant two point lead for Mr McCain, Abramowitz said: “One reason for the dramatic difference between the two recent CBS polls is that the two samples differed fairly dramatically in terms of partisan composition."
The first sample was 35.2 per cent Democratic, 26.2 per cent Republicans, and 38.6 percent independent.
Compiled from websites by JOHN NGIRACHU