Compare PPP's last two polls of the GOP presidential primary in Iowa.
PublicPolicyPolling, conducted 4/15-17, MoE +/- 4.8%
Michele Bachmann 10%And now more recent.
Newt Gingrich 15%
Sarah Palin 15%
Ron Paul 15%
Tim Pawlenty 9%
Mitt Romney 25%
Someone else/Undecided 11%
PublicPolicyPolling, conducted 5/27-30, MoE +/- 4.5%
Michele Bachmann 11%There is not very much change between these two polls excepting Cain. Romney (-4), Paul (-6) and Gingrich (-3) all lose a bit of strength, while Palin, Pawlenty and Bachmann exhibit little change.
Herman Cain 15%
Newt Gingrich 12%
Jon Huntsman 0%
Sarah Palin 15%
Ron Paul 8%
Tim Pawlenty 10%
Mitt Romney 21%
Someone else/Undecided 8%
The big story here is Herman Cain's rise- his sudden charge to 15% in Iowa largely occurred under the media's radar. His favorables went from 15/9/75 in the April poll to 38/24/38 in May.
What caused the change? A debate.
I think pundits made a big mistake in downplaying the influence of the first, poorly attended debate of the presidential primary at the beginning of May. The two biggest changes in our poll numbers come from two participants- Paul and Cain.
Viewers of the debate would note that Herman Cain had pretty solid answers during that event (his answers are compiled here). The moderators of the event gave Cain the least number of negative questions going after his record of any of the participants (the sole question of this nature was asking if he was electable, noting his position against abortion in cases of rape or incest). Those pundits that did pay attention to the event declared Herman Cain the winner.
Contrast this with Ron Paul. His favorables in April were 55/17/28, strikingly positive for a fairly well-known candidate. By May this had changed to 42/29/29, a -25% drop from his +38 to +13. Paul has hired staff, visited Iowa four times and raised a significant chunk of money since the last poll. The drop in favorability is counterinuitive until one considers the May 5th debate.
Before I go any further, I believe most readers here know that I have significant libertarian tendencies and have been a supporter of both Paul and Gary Johnson for much of this primary season. I personally had few policy problems with Ron Paul's answers.
The moderators had several critical questions for Paul (You can see all of his answers in this Youtube compilation here).The Congressman gave muddled answers to questions on cutting defense spending ("What would you leave for the federal government to do") and on drug legalization. These controversial subjects are Paul's biggest points of contention with the electorate he must win over; to overcome a natural skepticism, Paul needs straightforward and clear talking points that make his position seem natural and logical. Dr. Paul failed to accomplish this in the first debate, and his favorables declined similarly.
This does not mean we should overstate the effect either. Paul still has a positive impression with Iowa GOP voters, and Cain is still not well-known by them. Romney as the frontrunner barely cracks 21% with several candidates in double-digits. We are eight months from the Iowa caucuses, and anything can still happen.