Former Secretary of State Hillary Rodham Clinton speaks at an event to support Rep. Bruce Braley, D-Iowa, right, in his senatorial race, Wednesday, Oct. 29, 2014, in Cedar Rapids, Iowa. (AP Photo/Matthew Holst)

Former secretary of state Hillary Clinton on Wednesday knocked Iowa Republican Senate candidate Joni Ernst for failing to meet with newspaper editorial boards in her state.

"You have a lot to be proud of in this state. You test your candidates," Clinton said during a campaign event for Democrat Bruce Braley. She added: "They have to be willing answer the tough questions, which Bruce has been willing to do and his opponent has not. It truly seems like it should be disqualifying in Iowa of all states to avoid answering questions."

Last week, Ernst, a state senator, canceled her meeting with state's biggest paper, the Des Moines Register. According to a campaign official, she did so because she believed the paper's editorial board had shown a bias against her in editorials over the past two months.

Rekha Basu, a Register columnist, wrote on Facebook that Ernst has "also begged off meetings with The Cedar Rapids Gazette and The Dubuque Telegraph-Herald."

Polls show Ernst and Braley, a congressman, are in a close race. The outcome could decide which party controls the Senate majority.