The future plans of the two Texans trying to win the hearts of Republicans could hinge on how they rate in Iowa. Brandon Rottinghaus is associate professor of political science at the University of Houston.
"If Rick Perry comes in fourth place or higher, I think that they can claim that they're still in the race. Ron Paul's a bit trickier. You know, Ron Paul has got a pretty significant chunk of people who are going to follow him anywhere he goes. The problem for Ron Paul is simply that the rest of the kind of Republican establishment and even the rest of the media establishment are not going to pay as much attention because he's not going to do as well in these other states."
Even in this day of campaigning through radio and television advertising and now social media, a lot of what the candidates have been doing in Iowa has been relatively old-fashioned — county-by-county visits by bus.
"This is really retail politics — knocking on doors, meeting people in diners."
Ed: "How is this for the candidates? You know, it is one-on-one — they can hear sort of unfiltered what people are wanting to come up and say to them."
"True, it definitely has been a very prime opportunity for the canddiates to get to know some voters and maybe hone their message a little bit. It also magnifies and multiplies the number of things that might go wrong. You might have supporters of the other campaign there yelling at you. You might have picketers outside the diner you're in. You do have the kinds of problems that go along with the kind of interpersonal relationship that politics creates."
Governor Perry heads to South Carolina to campaign for that state's primary after the Iowa caucuses. Several other GOP candidates will head east for the New Hampshire primary, which is nine days after Iowa.