Republican presidential candidate and Wisconsin Gov. Scott Walker speaks at the Iowa State Fair, where he encountered protesters over his record in Wisconsin. Charlie Neibergall/AP hide caption

itoggle caption Charlie Neibergall/AP

Democratic presidential candidate Hillary Clinton speaks at the Iowa Democratic Wing Ding at the Surf Ballroom on Friday. Appearing at the Iowa State Fair on Saturday, she said the controversy over her emails was the "usual" politics. Charlie Riedel/AP hide caption

itoggle caption Charlie Riedel/AP

Brenda Hummel and her 7-year-old daughter Andrea in their home near Des Moines, Iowa. Andrea was born with severe epilepsy and gets her health care through Medicaid. Clay Masters/Iowa Public Radio hide caption

itoggle caption Clay Masters/Iowa Public Radio

As candidates, staff and media flood Iowa, there will inevitably be photo ops with grain silos and bales of hay. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

Men in hazardous materials suits load dead poultry to be buried at Rose Acre Farms Inc., just west of Winterset, Iowa, on May 11. John Gaps III/AP hide caption

itoggle caption John Gaps III/AP

Wisconsin Gov. Scott Walker offers cheese and ice cream to guests in his hospitality room at the Iowa Lincoln Day Dinner in Des Moines on Saturday. Charlie Neibergall/AP hide caption

itoggle caption Charlie Neibergall/AP

A view of the eastern entrance to the Ohio Statehouse. Bob Hall/Flickr hide caption

itoggle caption Bob Hall/Flickr

Former Florida Gov. Jeb Bush speaks to members of the media during a two-day swing through Iowa that had all the trappings of a presidential campaign. Charlie Neibergall/AP hide caption

itoggle caption Charlie Neibergall/AP

Kent Sorenson says he was paid for his endorsement of Ron Paul in the 2012 presidential campaign — and that the exchange was hidden from the public. Charles Dharapak/AP hide caption

itoggle caption Charles Dharapak/AP

Farmer Seth Watkins (left) and agronomist Matt Liebman stand amid native prairie grasses near Des Moines, Iowa. The conservation strip is used to stop soil erosion. John Ydstie/NPR hide caption

itoggle caption John Ydstie/NPR

The city of Davenport, Iowa, is home to about 100,000 people. The city's mayor, Bill Gluba, wants the city to shelter some of the unaccompanied minors who have crossed the southern border of the U.S., but some members of the City Council oppose his efforts. scmcgee/Flickr hide caption

itoggle caption scmcgee/Flickr