I caught this video a few days ago.
I figured it was a "gotcha" because of McCain's infidelity during his first marriage. The answer he gives is the answer I'd give - he refuses to comment. Then tasteless Katie Couric gives that sunny grin and uses a gossipy tone and presses, so McCain follows with "Judge not". He and I are in the same spot here. we're not hypocrites. We made these mistakes and we are not going to rail against others who do the same.
But I remember wondering about how stuck Obama seems on it. I considered that he was simply trying to not come off as "high and mighty" about it. Sometimes you can turn people off by seeming too perfect (LOL! You know I think that's "The One"'s biggest problem - not!)
Now it seems there might have been another reason for the Obamassiah to stutter.