The writeup on this poll is kind of confusing. See here:
http://news-releases.uiowa.edu/2011/april/042711hawkeye_poll_GOP.htmland here:
http://news-releases.uiowa.edu/2011/april/042711GOP_topline_3.pdfIt looks like they did both a national poll and a poll of Iowa and merged them together. Or if you prefer, they did a national poll with a big oversampling of Iowa. And they polled all voters, not just Republicans. But of course, the Republican #s are the relevant ones, so those are the ones I'll list.
Republican presidential preferences in Iowa:
Romney 24%
Huckabee 23%
Palin 15%
Gingrich 9%
Pawlenty 8%
Paul 2%
Barbour 1%
Bachmann 0%
Daniels 0%
Republican presidential preferences nationally:
Romney 17%
Huckabee 16%
Paul 13%
Palin 11%
Gingrich 9%
Bachmann 3%
Pawlenty 3%
Barbour 2%
Daniels 1%
That's unusually strong #s for Romney in Iowa, but the Iowa subsample is so small that I doubt it means anything.