Oct. 22, 2010
All Pre-election polls interview registered voters (RV); likely voter (LV) polls are a sub-sample based on the likely voter cutoff model (LVCM). But the widely-followed realclearpolitics.com and other election sites show only the LV samples. RV poll listings are being phased out. It happens in every election cycle.
Generic polls from Gallup, AP, FOX, Reuters and ABC show that a solid majority of registered voters excluded from the LV subset are Democrats.
The House and Senate forecast models provide a comprehensive analysis of Registered Voter (RV) and Likely Voter (LV) polls. The assumption is that the election is held today.
Based on the latest LV polls, the Monte Carlo Simulation indicates projects a 51-47 seat Democratic majority. The GOP has a 4% probability of winning the Senate.
Based on mix of RV and LV polls the Democrats will have a 53-45 majority. The GOP has a 0% win probability.
CNN/Time lists 18 RV polls in which the Democrats lead by 5.2%. The Democrats trail by 1.1% in the corresponding 18 LVs.
House Generic Ballot
Starting Oct. 11, RCP no longer includes RV polls in the Generic Average.
The GOP has a 1.4% lead in the latest 22 RV polls and a 6.9% margin in the latest 27 LV polls.
Based on the latest 27 LV Generic polls, the GOP has a 99% probability of winning the House (234 seats). Based on the latest 22 RV polls, the GOP has a 69% win probability (222 seats).
In 2010, 40 of the 175 polls listed are Rasmussen LV polls in which the GOP leads by 8.1%. The GOP leads by just 2.3% in the other 135 polls. Apparently RCP believes that Rasmussen is a non-partisan pollster since he is included in the RCP average of “non-partisan affiliated polls”.
In the latest Gallup LV polls, the GOP leads by 53-42 in the high turnout model and 56-39 in the low turnout model. The full 3000-sample RV is not shown. The GOP leads by 47-44. The Democrats lead by 48-35% among the 1100 RV respondents who were not included in the LV cutoff.
Not a single Zogby poll is listed by RCP. The latest Zogby LV shows a 45-45 tie.
Voter Turnout (LVCM)
The majority of registered voters who do not pass the LVCM screen are Democrats.In 2004 and 2008, the Democratic share of unlikely voters closely matched the share of new voters.
The projected turnout of registered voters is the ratio:
Turnout = LV poll sample / RV poll sample
The Democratic two-party share of unlikely voters is the ratio of unlikely Dem RVs to unlikely Dem and GOP RVs.
Dem share = Dem [RV-LV] / (Dem [RV-LV] + GOP [RV-LV])
Pollster Turnout Projections
Pollster Turnout Dem share of unlikely RV
Gallup 67% 58%
AP 63% 58%
FOX 57% 55%
Reuters 84% 56%
ABC /Wash Post 76% 71%
Average 69% 60%
In 2004, final pre-election polls indicated that Kerry had a 58% share of unlikely RV. The Preliminary 12:22am National Exit Poll showed that Kerry had a 57% share of first-time voters and others who did not vote in 2000.
In 2008, final pre-election polls indicated that Obama had a 73% share of unlikely RV. The Preliminary indicated that he had a 71% share of first-time voters and others who did not vote in 2000.