Obama's weak response to the Ayers attack

Obama's campaign defended him this morning and all throughout the day by saying that he didn't even know Ayers was a radical when he first met him, as well as downplaying even more the ties that the two individuals have.
I think this is absolutely lame, for a campaign that has had months to come up with better, more airtight explanations to ease voter concerns (remember this come up during the April Democratic Primary Debate in Pennsylvania) and they HAD to know that McCain would use the Ayers connection sooner or later, this is the best they can come up with? Arguably the most disciplined and effective political campaign in modern times has some lame-duck plausible deniability spin?
Palin and McCain, with the help of a willing media aching for more attack politics to feed their evening news cycles, have been hammering this point home today. No doubt, if this is the best they can do (as well as a "you know bad people too" argument) we will be hearing about this story MUCH more.
I wouldn't be surprised if Bill Ayers and Jeremiah Wright came up every single day between now and Novemeber 4th.
Who knows if this will come up tomorrow during the debate, no doubt John McCain will try and throw in a few "who is this guy really?" jabs. Or maybe Obama is saving his best zingers for tomorrow night, either way, the race is getting into the deep end of the mud pit, and everyone is going to get dirty.