Is there an IVR/Live Telephone Interview divide in Republican primary polling?

While PPP has shown a remarkable surge in Bachmann’s performance, with her pulling into a one point lead nationally, many other pollsters have found only a moderate surge. Bachmann reaches only 8% In a McClatchy/Marist poll (6/15 - 6/23), 11% in a Fox News Poll (6/26 - 6/28) and 14% in a Quinnipiac poll (7/5 - 7/11). On the other hand, Rasmussen (6/14) also found a larger surge for Bachmann, with her polling at 19% despite the poll having been conducted only right after the last debate as Bachmann’s surge was just beginning. However, the Rasmussen poll did have a large Romney lead. Nevertheless, Bachmann’s strongest showings have both been in IVR polls.

Similarly in Iowa, IVR pollster Magellan Strategies has Bachmann at 29%, almost double Romney’s 16% while live telephone interview pollsters have found Bachmann either tied or with only a small lead on Romney. In New Hampshire, the evidence is more of a mixed bag with PPP finding Bachmann closest to Romney with 18% to his 25%, while Magellan finds Bachmann with her lowest support at 10%. Magellan’s poll of New Hampshire was conducted right after the debate, so Bachmann’s showing might be stronger if they were to re-poll this week.

It’s not just Bachmann for whom IVR polls have shown stronger support. At the height of Cain’s surge, PPP showed him stronger relative to Romney than all other pollsters. No other IVR polls were conducted nationally at this time. Similarly, PPP and Rasmussen were the only pollsters to find Donald Trump alone in the lead at his height.

Bachmann, Cain, and Trump all have had appeal to the Tea Party wing of the Republican Party. It’s possible that IVR polls could be showing a stronger performance for the right wing candidates than live telephone interview pollsters, though this is far from certain. The Magellan New Hampshire poll and the recent Rasmussen national poll showing a large lead for Romney offer contradictory evidence. However, this might be attributable to both polls occurring right after the debate before her momentum could fully build. While more evidence is needed, it’s worth keeping an eye on to see if the divide persists.