It's helpful to remember that there are a huge chunk of voters who make their decisions based on looks, speaking voice, ability to tell a joke, etc. Therefore, a candidate who is attractive has an advantage over others.
The looks factor in Iowa isn't what's most important, though. Iowa caucus voters are more focussed on issues and ideology.
What WILL make the difference is how good your organization is, and both Edwards and Romney are at an advantage with their ground troops.
While Freepers dissect every word ever mouthed in the entire history of a candidate others are more impressed by a hair style, dress, or "isn"t he handsome" comment. And these people are allowed to vote as well!!