A Mitt supporter notes:

It seems there is another reason Romney’s win is significant: the 2nd, 3rd and 4th place finishers all came from mid-or-mountain-west states near, and with similar demographics to, Iowa: Arkansas, Kansas, Colorado. It is all the more impressive that an ex-Governor of Massachusetts could organize and rally such a big win on far from home turf.

UPDATE: A different view:

As an Arkansan living in Iowa, the Romney supporter who claims that the two states have a similar demographic is off base. One big difference is that Arkansas is 16% black, while Iowa is, shall we say, not. Of course, the Romney person could say that they only meant the Republican-leaning demographic, but there is still a big difference between Southern evangelicals and reserved Midwesterners. Could a Baptist minister be elected governor in Iowa?