CNN

Watch Carol Costello's report on the negative campaign ads.

(CNN)—Barack Obama is being slammed in a number of Republican campaign commercials having nothing to do with the Hillary Clinton or John McCain’s bid for the White House.

In the last week alone, Obama made cameo appearances in 8-10 Republican attack ads across the country, but what kind of effect, if any, is it having on the presidential race? CNN’s Carol Costello reports.