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July 21, 2006

Quinnipiac's Latest Connecticut Poll

It’s been a busy week, with far more interesting topics than I have had time to blog.  Let's start with the Quinnipiac Poll released yesterday that puts Ned Lamont ahead of Sen. Joe Lieberman among likely Democratic primary voters in Connecticut by a "razor thin" margin (51% to 47%).   The Democratic primary results are part of a larger survey of 2,502 registered voters in Connecticut that includes many more questions including hypothetical general election match-ups for both Senate and Governor.   But the Lieberman Lamont race is the one everyone seems most interested in, so let me add a few comments. 

Regular readers will remember the recent post about the difficulty of polling in this race. This latest release helps clarify a few things, at least with respect to the Quinnipiac poll, which uses a methodology similar to that used by the national public pollsters.  Doug Schwartz, director of the Quinnipiac poll, confirms by email that they used a random digit dial (RDD) methodology to draw a sample of every household in Connecticut with a working landline telephone and then interviewed 2,502 respondents that self-identified as registered voters.  Of these, 962 (or 38%) identified themselves as registered Democrats. 

If I'm reading the statistics correctly, that percentage of Democrats among "active" registered voters reported by the Connecticut Secretary of State last year was lower (33%).  But keep in mind that both the anecdotal reports of unaffiliated voters switching their registration to Democrat in recent weeks and the possibility over-reporting of partisan registration due to the sort of "social discomfort" that often leads some respondents to say they voted when they didn't.

From the 962 self-identified registered Democrats, Quinnipiac identified 653 as "likely Democratic primary voters."  According to Schwartz, that process involved "questions that measured intention to vote, interest in the election, and interest in politics."  In other words, those indicating the greatest interest and likelihood to vote in the primary were designated likely voters.  "Our likely voter selection was guided by what has worked well for us in the past," Schwartz added.  "We used screens that have done a good job in predicting past elections.  They are not meant to try to predict the voter turnout."

That last point is important.  As I argued just before the 2004 elections, the process of calibrating a poll's likely voter model to match a specific level of turnout is inexact and involves far more art than science.  The Quinnipiac pollsters made an educated guess about turnout and adjusted their models accordingly.  But we should not assume that the "cut off" they used (68% of registered Democrats) amounts to a prediction of the level of turnout. 

Although most pollsters will tell you to be cautious about surveys just before this sort of election, there are two sets of conclusions we can make from these data:

  • First, whatever we might think about how well the Quinnipiac poll models turnout, they have done so consistently.  So the trends in the survey are meaningful and indicate that Lamont has clearly made significant gains since early June, when Lieberman led by 15 points (55% to 40%).
  • Second, the Quinnipiac poll shows that the level of turnout will matter.  For example, among the most likely Democratic primary voters, Lieberman gets a net negative rating (35% favorable, 39% unfavorable).   But among all Democratic identifiers,** Lieberman is more popular  (40% favorable, 29% unfavorable).   Similarly, likely Democratic primary voters are closely divided on whether Lieberman "deserves to be reelected" (46% yes, 45% no), while all Democrats are more positive (51% yes, 37% no).

All of this provides an important warning to all those scrutinizing the polls that may be coming out of Connecticut over the next few weeks.  Be careful about comparing results from the Quinnipiac poll to those we may see from other pollsters, and vice versa.  Poll to poll variation across polls done by different polling organizations may have more to do with differences in the way they define likely voters than with real trends. 

Finally, both campaigns have their own pollsters and are presumably conducting their own tracking polls.  It would be truly interesting to see how those results compare and contrast with the public polls, since I assume (though do not know for certain) that they are drawing samples from registered voter lists rather than using the RDD methodology.  Unfortunately, at this stage campaigns usually keep their internal surveys under tight wraps.  Another topic for another day. 

** The Qunnipiac release includes tabulations of the results by party.  According to Doug Schwartz, those tabulations are based on a question about party identification (""Generally speaking, do you consider yourself a Republican, a Democrat, an independent, or what?") rather than the question about party registration they use to help identify likely voters ("Are you registered as a Republican, Democrat, some other party or are you not affiliated with any party?").

Related Entries - Likely Voters, The 2006 Race

Posted by Mark Blumenthal on July 21, 2006 at 10:51 PM in Likely Voters, The 2006 Race | Permalink

Comments

Question - I haven't heard anyone suggest that the turnout is likely to be as high in this race as the Q-Poll indicates. Do you think that lower turnout favors Lamont (which seems to be conventional wisdom here), or is Lamont's lead a function of including too many voters in the "likely voter" screen?

Posted by: matt | Jul 22, 2006 5:20:43 PM

I think Conn. has the chance to put a stop to this war.If Lamont was to upset Liberman, it would be a shot heard around the world.Otherwise it will be a foot note. Jim DuffyVeteran WW2 and Retiree NY Times

Posted by: Jim Duffy | Oct 10, 2006 8:41:49 AM

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