Republican U-S Senate candidate Greg Ganske last night asked his opponent, Democrat Senator Tom Harkin, to “come clean” about the details of a taping scandal. The two candidates met face-to-face in their first debate of the campaign season last night on W-O-I radio, and Ganske directly asked Harkin whether he had anything to do with the secret taping of a Ganske fundraising meeting.Ganske said Harkin needed to tell Iowans what he knew, and when he knew it. Harkin acknowledged “mistakes had been made” and but he said no crime had been committed.Harkin said it was time to raise the campaign above bitter, partisan politics and start talking about the issues. Ganske persisted, asking specific questions, like whether Harkin had taken precautions to ensure evidence isn’t being shredded or destroyed.Harkin responded.Harkin said there’s a reason Ganske keeps harping on the issue. Harkin said it’s because Ganske doesn’t want to talk about his record. After the debate, Ganske kept pressing the issue, and Harkin was asked by a reporter why he didn’t use last night’s debate to apologize to Ganske in person. Harkin said he had apologized to Ganske last week, and Harkin said “usually when someone apologizes, you’re man enough to accept it.” A Des Moines Register poll released this weekend showed Harkin has opened a 20-point lead over Ganske (54 to 34 percent) and some of those who answered the survey did so after the taping controversy became public knowledge.