Unfortunately, the McCain campaign has stooped to levels McCain himself had pledged never to reach, which is for lack of a better term 'character assassination' of Barack Obama. This happens when campaigns have nothing left and are behind. Some times it works, some times it does not. But beware, if Sen. Obama is forced to respond in kind, I'll bet he has ads in the vault that are ready to go at a moment's notice. McCain has plenty of old acquaintances and even those he calls friends that he admires, such as G. Gordon Liddy and a number of right-wing evangelicals and preachers (I imagine this is why he has put Rev. Wright off limits in his ads) who have made numerous inflammatory comments over the years that most would say rival what Rev. Wright has said on a few occasions.
But there are others that are not as well known. Check here if interested in some of McCain's associations that rival Obama's relationship on educational boards with Bill Ayers. I wonder why the press has not picked up on these?