Corporations , unions , special interest groups can fund campaign advertising anonymously . Comment: Republicans opposed bill to force disclosure of donors ' names and amounts , she writes . Like any mom , I was more than a little mad and demanded an explanation . The rule of thumb is , McCaskill says , if you ca n't find out who 's paying for the ad , do n't believe it .
Corporations , unions , special interest groups can fund campaign advertising anonymously . Comment: Republicans opposed bill to force disclosure of donors ' names and amounts , she writes . The rule of thumb is , McCaskill says , if you ca n't find out who 's paying for the ad , do n't believe it .