To date, only the last Selzer poll over a month ago and a couple of the Suffolk tracking polls have been near the 50% Indy split which should occur on election day. The daily Suffolk tracking polls have been particularly confusing as they have varied from 37% to 48.5% Indy split.
Why is virtually every poll missing the right mix of Independent voters?
In New Hampshire, undeclared voters (Independents) may vote in the GOP primary Tuesday. Currently they make up 42% of all registered voters in the state. Traditionally, the percent of independent voters in a NH primary when both Democratic and Republican primaries are contested is very similar to the percent of registered independent voters. However, when one party has an unchallenged incumbent (like 1996 with President Clinton or 2004 with President Bush), the percent of independents in the opposing parties primary goes way up. See stats below. % of Registered voters comes from state controlled lists (often reported via news services). The % of actual voters in a primary comes from exit polls.
|Year||% of All Voters||% of GOP Primary||% of Dem Primary|
The range of independent turnout for 2012 GOP Primary is based on linear extrapolation from the 1996 and 2004 primaries with the low number assuming a similar ratio of % in the GOP primary vs. Registered Voters from 1996 while the high number assuming a similar ration of % in the Dem Primary vs. Registered Voters from 2004.
Now, what are pollsters using as their ratio of Independents for next Tuesday's contest? What would the difference be if they had a different overall Indy ratio (based on their own candidate specific results by party breakdown)? See below:
|Pollster||% of Independents||Poll's Romney Lead||Romney Lead w/56% Indies|
Although some pollsters provided Indy vs GOP breakdowns at the poll level, some did not also breakdown splits by candidate by Indy vs. GOP so they have a ?? in the left column.
Those with UNKNOWN may have even excluded ALL non-GOP registered voters as CNN has done for every Iowa poll. Take those polls with a HUGE grain of salt.