The poll was conducted by American Research Group (ARG)

Sample Size: 600 completed telephone interviews among a random sample of likely Republican caucus goers living in Iowa (517 Republicans and 83 no party (independent) voters).

Sample Dates: September 22-27, 2011

Margin of Error: ± 4 percentage points, 95% of the time, on questions where opinion is evenly split.

September 2011

Romney 21%

Bachmann 15%

Perry 14%

Ron Paul 12%

* * * *

Comparison with July poll

Bachmann 21%

Romney 18%

Paul 14%

Palin 11%

Gingrich 8%

Perry 2% (not an official candidate at the time)