From the GOP website: http://www.iowagop.net/straw.poll.asp says that:
When a voter enters a credentialing area they will be asked to show their valid Iowa Driver’s License, Military ID or a student ID from an Iowa College or University.
Once they show one of the above forms of ID’s, voters with an Iowa Driver’s license or state issued ID will be scanned in order to prevent someone from voting with that same ID at another voting location. Voters with a military ID, student ID, or if their driver’s license does not scan properly will be required to fill out a voter registration form before receiving their ballot.
Folks: Ron Paul got 9% of the total votes. The voters were not screened by party affiliation. Republicans, Democrats, Libertarians, Communists, or anybody else of any persuasion that resides in Iowa was eligible for voting.
I doubt that Ron Paul would get 9% of strictly Republican votes.