CBN's David Brody talked with Barack Obama about attacks on his wife, Michelle. Obama said, "I think families are off limits. I would never consider making Cindy McCain a campaign issue, and if I saw people doing that - I would speak out against it. And the fact that I haven't seen that from John McCain I think is a deep disappointment."
CBN has more details here.
This video is from CBN, broadcast June 18, 2008.