The Iowa caucuses are the first vote in the long haul to the presidential election in November.
University of South Florida political science professor Susan MacManus is there, and says she's sensing a lot of voter anxiety about the economy - and their own personal security.
"People just don't feel that they have been a part of the economic recovery that supposedly happened after the great recession, and that's what we're seeing all over the country - a frustration about that," she said.
"But you also have a bit of anxiety and fear about the security of people - the terrorism problem that's hit American soil."