Results from the most recent Democrat-commissioned poll of voters in the redrawn 47th congressional district were released yesterday and they show Democratic California State Senator Alan Lowenthal in a 20 percent lead over Republican 3rd District City Councilmember Gary DeLong.
But today, DeLong released another poll—this one commissioned by his campaign—that put DeLong nearly 10 points above Lowenthal. With such a drastic disparity between these two survey results (and among others released since the two emerged from the primaries in June), it's hard to know who is actually in the lead and by how much.
Factors such as methodology, sample quality and question-wording can all have an effect on the outcome of polls like these and with each one subject to the biases of internally-commissioned surveys, it's hard not to feel like comparing the poll data in the 47th congressional race is an apples to oranges situation.
The most recently conducted poll, for example, was the one that put Lowenthal in the lead by 20 percent—the largest gap between the two candidates ever reported. Goodwin Simon Strategic Research (which conducted the poll on behalf of Lowenthal's campaign) says it telephone-surveyed 400 likely voters between August 16 and August 19 with a head-to-head vote question "in which voters were told only the candidates' names and actual ballot titles." In this question, Lowenthal lead DeLong 51 percent to 31 percent. The survey also said that Lowenthal lead DeLong by 20 percent among independent voters.
The results of an internally-commissioned survey conducted from from June 28th through July 3rd and released by the DeLong campaign today, however, say that the Republican candidate "is well-positioned for a November victory," leading Lowenthal 53 percent to 44 percent. It was not stated how the questions were presented to the pollers, but the Probolsky Research-conducted survey did state that it called both cell phone and land lines and also surveyed voters in English, Vietnamese and Spanish to match their language preference.
To make things even more confusing, DeLong has previously released poll data from a Probolsky Research survey it commissioned that was conducted during the exact same time period (June 28 to July 3) that placed Lowenthal at a close, three-percent lead over DeLong. Details of survey methods used in that survey, however, were not available.
And a few weeks later, the Democratic Congressional Campaign Committee pushed back with its own survey—this one was automated and only polled 259 people—that reported Lowenthal's lead to be a much-wider 11 percent.
So now that we know that both sides think they are winning, is it time to request an independent third-party poll in this district?
An up-to-date chart from PollTracker is below (does not yet include DeLong's winning poll results, which were released this morning).