In June 2012 in IA it was
Bachmann 21% (won straw poll)
Shortly after the Straw Poll and after Rick Perry’s Entry, but before Perry had the “3 points” debate meltdown
After Perry’s fall to the wayside and Herman Cain’s 9-9-9
but before Romney’s insiders and pals in NJ did him in with the made up scandals
After Newt comes out of nowhere and surges right before Christmas but before he dropped back down again after comments during the week before the Caucus
Caucus day. Rick Santorum griped about being the only one not to get a chance to surge. The surge happened a little unexpectedly on Election day and gave him a 25 vote win.
So Polls at this stage are meaningless.
The only generalization we can make is that IA has roughly 25% of RINO voters, about 20-30% Social Issues only conservatives, 15-20% libertarians that may or may not actually be as insane as RuPaul and 20-25% up for grabs that gets distributed to the other candidates.
This means a Republican that wins IA in a crowded field with 40% or more of the vote looks strong.