Thursday, September 30, 2010
Is the New Washington Post Poll "Out of Whack?"
The Post does not provide a breakdown of party ID among likely voters, but polling director Jon Cohen provided that data to me today. Party ID was 50% Dem, 26% Rep, and 23% Ind. The Post data also lacks cross tabs showing the level of support for each candidate by party ID among likely voters, Cohen provided that as well - O'Malley is winning 87% of Dems, 5% of Reps, and 31% of Inds, Ehrlich wins 10% of Dems, 93% of Reps, and 54% of Inds.
This is crucial information and suggests that the Washington Post is overstating Democratic turnout and understating Republican turnout in 2010. Consider - the 2004 Maryland turnout (a decent Republican year)was 48% Democrat, 30% Republican, and 22% Independent; the 2008 turnout numbers (an incredible Democratic year) were 51% Democrat, 28% Republican and 21% Independent.
So the Post sees a 2010 electorate that every bit as Democrat as was 2008 and less Republican than either the bad year of 2008 or the good year of 2004. In other words, in a year marked by a tremendous enthusiasm gap between Democrats and Republicans the Post thinks that Democrats will rival their 2008 turnout and Republicans will not even be able to reach their's - this is just not a reasonable assumption.
Those differences may seem slight, but based on the cross tab data provided by Jon Cohen it is possible to model the Post's data based on a turnout dynamic like 2004 and 2008. I've done this in Tables One through Four below.
Using the 2008 turnout assumptions (Table Four) the results of the poll become 54% O'Malley to 44% Ehrlich - essentially the margin reported by the Post. This leads me to believe that the Post is assuming/modeling a turnout dynamic similar to 2008 - and that seems highly unlikely in the current political environment. This primary season has been marked by historic levels of GOP voter turnout and in key races in VA, NJ, and MA Democratic turnout was well off of the 2008 levels while GOP turnout was steady.
For these reasons I would argue that 2004 is a much more likely scenario - and that would make this a 4 point race and within the margin of error.
The Post poll also found that Ehrlich is winning just 10% of Democrats. That seems low, in the Democratic primary just two weeks ago fully 14% of Democrats voted against O'Malley and for two unknown candidates. If one assumes that Ehrlich wins 14% of Democrats (a number well below the roughly 22% he won in 2002 and the 15% he won in 2006) the poll results become 51% to 49% (Table Three).
I'd like to thank John Wagner and Jon Cohen for being so willing to speak with me about the poll and for being so accessible.