It's all Barack Obama's fault.
Not too surprising to hear John McCain blame his own campaign's negativity on Obama and his campaign's having opted out of the series of town halls McCain proposed. Nor was it too surprising to hear the Republican nominee go after Rep. John Lewis, D-Ga., saying -- while choking up -- that the former civil rights leader's criticism of the McCain camp was out of the bounds of acceptable discourse and should be repudiated by Obama. He's been out saying that already, ignoring the substance of the criticism in order to just call it unfair and unacceptable.
But a conversation about negative campaigning is Obama's turf; poll after poll has shown that Americans think he's been telling Americans about what he'll do as president, while at the same time they believe that McCain has just been attacking his opponent. And Obama did a good job refuting the charges and making McCain out as the negative campaigner.
As a side note -- this is just my opinion, but I really didn't like the question moderator Bob Schieffer asked in order to prompt this discussion. He repeated the attacks the two have leveled at each other and then all but taunted them to say it directly to each other. He wasn't just trying to get them to fight; he was trying to get them to make news by attacking each other, to make the debate he's moderating the liveliest of the cycle, and to me, that's just too much involvement on his part.