Obama is the real Christian in this race. Palin and McCain are proving their lack of Christianity right before our eyes when they smear Obama because he was on a board with Bill Ayers. Obama's relationship with Bill Ayers was absolutely, 100% reflective of Obama's Christianity in action. This is the correct response to the Ayers smear for Christians and those who like to think they are Christians.
Christianity is all about redemption. There is NO point to Christianity without redemption. Redemption means that after we fail, we can pick ourselves up, be forgiven, start over and do better. The whole point of Christianity is that we're human - we will fail.... BUT we are not permanently lost; we are forgivable and we get a second (third, fourth, fifth.....seventy times seven) chance.
Forgiveness is crucial to redemption. Christians MUST forgive. It's mandatory. As a Christian, it's the basic belief that if a person does something terrible and later changes his ways, that the sin can be forgiven. That doesn't necessarily mean forgotten, but it does mean that the person can be welcomed back into the community. So, Bill Ayers did his time. He went on to create a life for himself that included worthwhile work in his community. Being on a board with him and having a cordial relationship doesn't imply that Barak Obama is a terrorist or in any way approves of what Bill Ayers did in the 60s when Barak was 8 years old. It implies that Barak Obama is a Christian, recognizing that the past sin does not need to mean the rest of your life is wasted.
What would our society be like if once a person commits a felony we never allow them any positive association again? How could a felon ever contribute anything in that society?
What does it say about Sarah Palin's and John McCain's Christianity that they are unable to distinguish Bill Ayers: University professor and charitable board member from Bill Ayers: 22 year old terrorist who thought violence could change the world? They can't acknowledge that the way Bill Ayers has lived the last 30 or so years might indicate that he has repented / reformed / changed his ways? That, my friends, is a very unchristian response.
Edit: My apologies to those who took offense at my analysis through a Christian lens. What I'm trying to do here is provide a frame of context that is relevant to a large group of McCain/Palin supporters - the Christian right. I don't advocate that frame of context as the only relevant context, although I do advocate the concepts of redemption and forgiveness. (Sorry if this doesn't make complete sense... I'm late for work.)