Something to note; Mccain does not say the BHO line, nor does he seem to promote it. at least, that's the facade he's giving. But the impression I get pretty distinctly is that he's deliberately directing the anger of his constituents in that direction. When he waves his arms around and corrects someone he looks like a hero to the media, but he never actively discourages any pundits or members of his own staff from using the slurs, for that matter.
The mood at his rallies lately has been murderous, as has been discussed over and over again; And the prevailing air is race. If Mccain really cared about this, he would spend a little more time than a quick media photop, admonishing a supporter while smiling to the cameras, and actually address this issue more thoroughly. Even going so far as to tell people that if this is the way they want to show their support for him, that he does not want it anymore. That's what the old John McCain would have done. But the new John McCain is a puppet of the GOP; He's been this way for four years, clutching to his party out of, what I'm guessing, is a fear of change, without recognizing or admitting that the party he is in today is not the party he joined forty or so years ago. Either that, or he wants the nation's highest seat so badly that he's willing to do anything and sacrifice anything and pay any price - even his own integrity, dignity, and good name - to reach that seat.
He should have run with Kerry in '04. It might have been another four years, but he could have slam dunked the presidency no matter what party he ran for.