At a campaign rally in Cincinnati, Bill Cunningham, a local conservative radio talk show host, referred scathingly and repeatedly to "Barack Hussein Obama" while he was warming up the crowd before McCain spoke.
Immediately after the event, McCain told reporters: "I absolutely repudiate such comments ... I will take responsibility -- it will never happen again. It will never happen again."
On another occasion, the North Carolina Republican Party planned to run a TV commercial linking Democratic gubernatorial candidates Richard Moore and Beverly Purdue with controversial comments made by Obama's longtime minister, the Rev. Jeremiah Wright.
Although McCain was critical of Wright and Obama's association with him early on, he said he accepted Obama"s later disassociation from him and stopped mentioning Wright.
The McCain campaign is acutely sensitive to the suspicion of some African-Americans and Democrats that in the heat of a close race down the stretch it -- or supporters not affiliated with the campaign -- will play the race card, something akin to the Willie Horton ad of 1988.
McCain has vowed that his campaign will not do so. He has also said he will condemn anyone who acts in that way on his behalf.