Because McCain is the media's favorite Republican and they love him. If McCain made a public statement demanding the ads be pulled he would get air time very quickly.
We haven't heard so much as a peep out of him.
I don't think that McCain would pull media time if it embarrassed the Dems. The media is for the Dems. They put up with McCain because they hope he runs on the Republican ticket so that they can slap at the right wing of the Republican party.
Does anyone here believe that if McCain were the Republican nominee anything would be any different about the media coverage of the Swiftvets? EVERYTHING would be the same.